Help for package TcGSA

Type: Package

Title: Time-Course Gene Set Analysis

Version: 0.12.13

Date: 2025年07月22日

Depends: R (≥ 3.0.2), ggplot2 (≥ 2.0.0)

Imports: lme4 (≥ 1.0-4), reshape2, GSA, multtest, cluster, cowplot, graphics, grDevices, gtools, stringr, splines, stats, utils

Suggests: BiocManager, foreach, parallel, doParallel, dearseq, knitr, GEOquery, rmarkdown

Description: Implementation of Time-course Gene Set Analysis (TcGSA), a method for analyzing longitudinal gene-expression data at the gene set level. Method is detailed in: Hejblum, Skinner & Thiebaut (2015) <doi:10.1371/journal.pcbi.1004310>.

License: GPL-2 | file LICENSE

Encoding: UTF-8

BugReports: https://github.com/sistm/TcGSA/issues

RoxygenNote: 7.3.2

VignetteBuilder: knitr

URL: http://sistm.github.io/TcGSA/

NeedsCompilation: no

Packaged: 2025年07月22日 16:11:25 UTC; boris

Author: Boris P Hejblum [aut, cre], Damien Chimits [aut], Anthony Devaux [aut]

Maintainer: Boris P Hejblum <boris.hejblum@u-bordeaux.fr>

Repository: CRAN

Date/Publication: 2025年07月22日 16:40:54 UTC

Time-course Gene Set Analysis

Description

This package implements TcGSA, an algorithm to analyze longitudinal gene-expression data at the gene set level.

Details

Package: TcGSA

Type: Package

Version: 0.12.13

Date: 2025年07月22日

License: GPL-2

The main function in this package is TcGSA.LR which performs Time-course Gene Set Analysis, and provide nice representations of its results (see plot.TcGSA and plot1GS ).

Author(s)

Boris P. Hejblum, Damien Chimits — Maintainer: Boris P. Hejblum

References

Hejblum BP, Skinner J, Thiebaut R, (2015) Time-Course Gene Set Analysis for Longitudinal Gene Expression Data. PLOS Comput. Biol. 11(6):e1004310. doi: 10.1371/journal.pcbi.1004310

Internal TcGSA Functions

Description

Internal TcGSA functions

Details

These are not to be called by the user.

MYheatmap.2 was adapted from the function heatmap.2 included in the package gplots, authored by: Andy Liaw, original; R. Gentleman, M. Maechler, W. Huber, G. Warnes, revisions; under the GPL-2 license.

Computing the Likelihood Ratios for the Gene Sets under Scrutiny

Description

This function computes the Likelihood Ratios for the gene sets under scrutiny, as well as estimations of genes dynamics inside those gene sets through mixed models.

Usage

TcGSA.LR(
 expr,
 gmt,
 design,
 subject_name = "Patient_ID",
 time_name = "TimePoint",
 crossedRandom = FALSE,
 covariates_fixed = "",
 time_covariates = "",
 time_func = "linear",
 group_name = "",
 separateSubjects = FALSE,
 minGSsize = 10,
 maxGSsize = 500
)
## S3 method for class 'TcGSA'
print(x, ...)

Arguments

expr

a matrix or dataframe of gene expression. Its dimension are nxp, with the p samples in column and the n genes in row.

gmt

a gmt object containing the gene sets definition. See GSA.read.gmt and definition on https://docs.gsea-msigdb.org/.

design

a matrix or dataframe containing the experimental variables that used in the model, namely subject_name, time_name, and covariates_fixed and time_covariates if applicable. Its dimension are pxm and its row are is in the same order as the columns of expr.

subject_name

the name of the factor variable from design that contains the information on the repetition units used in the mixed model, such as the patient identifiers for instance. Default is 'Patient_ID'. See Details.

time_name

the name of a numeric variable from design that contains the information on the time replicates (the time points at which gene expression was measured). Default is 'TimePoint'. See Details.

crossedRandom

logical flag indicating whether the random effects of the subjects and of the time points should be modeled as one crossed random effect or as two separated random effects. Default is FALSE. See details.

covariates_fixed

a character vector with the names of numeric or factor variables from the design matrix that should appear as fixed effects in the model. See details. Default is "", which corresponds to no covariates in the model.

time_covariates

a character vector with the names of numeric or factor variables from the design matrix that should appear as fixed effects interaction with the time_name variable in the model. See details. Default is "", which corresponds to no covariates in the model.

time_func

the form of the time trend. Can be either one of "linear", "cubic", "splines" or specified by the user, or the column name of a factor variable from design. If specified by the user, it must be as an expression using only names of variables from the design matrix with only the three following operators: +, *, / . The "splines" form corresponds to the natural cubic B-splines (see also ns ). If there are only a few timepoints, a "linear" form should be sufficient. Otherwise, the "cubic" form is more parsimonious than the "splines" form, and should be sufficiently flexible. If the column name of a factor variable from design is supplied, then time is considered as discrete in the analysis. If the user specify a formula using column names from design, both factor and numeric variables can be used.

group_name

in the case of several treatment groups, the name of a factor variable from the design matrix. It indicates to which treatment group each sample belongs to. Default is "", which means that there is only one treatment group. See Details.

separateSubjects

logical flag indicating that the analysis identifies gene sets that discriminates patients rather than gene sets than have a significant trend over time. Default is FALSE. See Details.

minGSsize

the minimum number of genes in a gene set. If there are less genes than this number in one of the gene sets under scrutiny, the Likelihood Ratio of this gene set is not computed (the mixed model are not fitted). Default is 10 genes as the minimum.

maxGSsize

the maximum number of genes in a gene set. If there are more genes than this number in one of the gene sets under scrutiny, the Likelihood Ratio of this gene set is not computed (the mixed model are not fitted). This is to avoid very long computation times. Default is 500 genes as the maximum.

x

an object of class 'TcGSA'.

...

further arguments passed to or from other methods.

Details

This Time-course Gene Set Analysis aims at identifying gene sets that are not stable over time, either homogeneously or heterogeneously (see Hejblum et al, 2012)in terms of their probes. And when the argument separateSubjects is TRUE, instead of identifying gene sets that have a significant trend over time, TcGSA identifies gene sets that have significantly different trends over time depending on Subjects.

Value

TcGSA.LR returns a tcgsa object, which is a list with the 5 following elements:

fit a data frame that contains the 3 following variables:
- LR: the likelihood ratio between the model under the null hypothesis and the model under the alternative hypothesis.
- CVG_H0: convergence status of the model under the null hypothesis.
- CVG_H1: convergence status of the model under the alternative hypothesis.
time_func: a character string passing along the value of the time_func argument used in the call.
GeneSets_gmt: a gmt object passing along the value of the gmt argument used in the call.
group.var: a factor passing along the group_name variable from the design matrix.
separateSubjects: a logical flag passing along the value of the separateSubjects argument used in the call.
Estimations: a list of 3 dimensions arrays. Each element of the list (i.e. each array) corresponds to the estimations of gene expression dynamics for each of the gene sets under scrutiny (obtained from mixed models). The first dimension of those arrays is the genes included in the concerned gene set, the second dimension is the Patient_ID, and the third dimension is the TimePoint. The values inside those arrays are estimated gene expressions.
time_DF: the degree of freedom of the natural splines functions

Author(s)

Boris P. Hejblum

References

Hejblum BP, Skinner J, Thiebaut R, (2015) Time-Course Gene Set Analysis for Longitudinal Gene Expression Data. PLOS Comput. Biol. 11(6):e1004310. doi: 10.1371/journal.pcbi.1004310

Examples


if(interactive()){
data(data_simu_TcGSA)
tcgsa_sim_1grp <- TcGSA.LR(expr=expr_1grp, gmt=gmt_sim, design=design, 
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=FALSE)
tcgsa_sim_1grp
summary(tcgsa_sim_1grp)
plot(x=tcgsa_sim_1grp, expr=expr_1grp, 
 Subject_ID=design$Patient_ID, TimePoint=design$TimePoint,
 baseline=1, 
 B=100,
 time_unit="H"
 )
 
tcgsa_sim_2grp <- TcGSA.LR(expr=expr_2grp, gmt=gmt_sim, design=design,
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=FALSE, 
 group_name="group.var")
tcgsa_sim_2grp
}

Parallel computing the Likelihood Ratios for the Gene Sets under Scrutiny

Description

A parallel version of the function TcGSA.LR to be used on a cluster of computing processors. This function computes the Likelihood Ratios for the gene sets under scrutiny, as well as estimations of genes dynamics inside those gene sets through mixed models.

Usage

TcGSA.LR.parallel(
 Ncpus,
 type_connec,
 expr,
 gmt,
 design,
 subject_name = "Patient_ID",
 time_name = "TimePoint",
 crossedRandom = FALSE,
 covariates_fixed = "",
 time_covariates = "",
 time_func = "linear",
 group_name = "",
 separateSubjects = FALSE,
 minGSsize = 10,
 maxGSsize = 500,
 monitorfile = ""
)

Arguments

Ncpus

The number of processors available.

type_connec

The type of connection between the processors. Supported cluster types are "SOCK", "PVM", "MPI", and "NWS". See also makeCluster .

expr

a matrix or dataframe of gene expression. Its dimension are nxp, with the p samples in column and the n genes in row.

gmt

a gmt object containing the gene sets definition. See GSA.read.gmt and definition on https://docs.gsea-msigdb.org/.

design

subject_name

time_name

the name of the numeric or factor variable from design contains the information on the time replicates (the time points at which gene expression was measured). Default is 'TimePoint'. See Details.

crossedRandom

covariates_fixed

time_covariates

the name of a numeric variable from design that contains the information on the time replicates (the time points at which gene expression was measured). Default is 'TimePoint'. See Details.

time_func

group_name

separateSubjects

logical flag indicating that the analysis identifies gene sets that discriminates patients rather than gene sets than have a significant trend over time. Default is FALSE. See Details.

minGSsize

maxGSsize

monitorfile

a writable connections or a character string naming a file to write into, to monitor the progress of the analysis. Default is "" which is no monitoring. See Details.

Details

This Time-course Gene Set Analysis aims at identifying gene sets that are not stable over time, either homogeneously or heterogeneously (see Hejblum et al, 2012) in terms of their probes. And when the argument separatePatients is TRUE, instead of identifying gene sets that have a significant trend over time (possibly with probes heterogeneity of this trend), TcGSA identifies gene sets that have significantly different trends over time depending on the patient.

If the monitorfile argument is a character string naming a file to write into, in the case of a new file that does not exist yet, such a new file will be created. A line is written each time one of the gene sets under scrutiny has been analyzed (i.e. the two mixed models have been fitted, see TcGSA.LR ) by one of the parallelized processors.

Value

TcGSA.LR returns a tcgsa object, which is a list with the 5 following elements:

fit a data frame that contains the 3 following variables:
- LR: the likelihood ratio between the model under the null hypothesis and the model under the alternative hypothesis.
- CVG_H0: convergence status of the model under the null hypothesis.
- CVG_H1: convergence status of the model under the alternative hypothesis.
time_func: a character string passing along the value of the time_func argument used in the call.
GeneSets_gmt: a gmt object passing along the value of the gmt argument used in the call.
group.var: a factor passing along the group_name variable from the design matrix.
separateSubjects: a logical flag passing along the value of the separateSubjects argument used in the call.
Estimations: a list of 3 dimensions arrays. Each element of the list (i.e. each array) corresponds to the estimations of gene expression dynamics for each of the gene sets under scrutiny (obtained from mixed models). The first dimension of those arrays is the genes included in the concerned gene set, the second dimension is the Patient_ID, and the third dimension is the TimePoint. The values inside those arrays are estimated gene expressions.
time_DF: the degree of freedom of the natural splines functions

Author(s)

Boris P. Hejblum

References

Hejblum BP, Skinner J, Thiebaut R, (2015) Time-Course Gene Set Analysis for Longitudinal Gene Expression Data. PLOS Comput. Biol. 11(6):e1004310. doi: 10.1371/journal.pcbi.1004310

Examples

 
if(interactive()){
data(data_simu_TcGSA)
tcgsa_sim_1grp <- TcGSA.LR(expr=expr_1grp, gmt=gmt_sim, design=design, 
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=FALSE)
 
library(doParallel)
tcgsa_sim_1grp_par <- TcGSA.LR.parallel(Ncpus = 2, type_connec = 'SOCK',
 expr=expr_1grp, gmt=gmt_sim, design=design, 
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=FALSE, 
 separateSubjects=TRUE)
summary(tcgsa_sim_1grp)
summary(tcgsa_sim_1grp_par)
}

Cluster the genes dynamics into different dominant trends.

Description

This function clusters the genes dynamics of one gene sets into different dominant trends. The optimal number of clusters is computed thanks to the gap statistics. See clusGap .

Usage

clustTrend(
 tcgs,
 expr,
 Subject_ID,
 TimePoint,
 threshold = 0.05,
 myproc = "BY",
 nbsimu_pval = 1e+06,
 baseline = NULL,
 only.signif = TRUE,
 group.var = NULL,
 Group_ID_paired = NULL,
 ref = NULL,
 group_of_interest = NULL,
 FUNcluster = NULL,
 clustering_metric = "euclidian",
 clustering_method = "ward",
 B = 100,
 max_trends = 4,
 aggreg.fun = "median",
 na.rm.aggreg = TRUE,
 trend.fun = "median",
 methodOptiClust = "firstSEmax",
 indiv = "genes",
 verbose = TRUE
)
## S3 method for class 'ClusteredTrends'
print(x, ...)
## S3 method for class 'ClusteredTrends'
plot(x, ...)

Arguments

tcgs

a tcgsa object for clustTrend, or a ClusteredTrends object for print.ClusteredTrends and plot.ClusteredTrends.

expr

either a matrix or dataframe of gene expression upon which dynamics are to be calculated, or a list of gene sets estimation of gene expression. In the case of a matrix or dataframe, its dimension are n x p, with the p sample in column and the n genes in row. In the case of a list, its length should correspond to the number of gene sets under scrutiny and each element should be an 3 dimension array of estimated gene expression, such as for the list returned in the 'Estimations' element of TcGSA.LR . See details.

Subject_ID

a factor of length p that is in the same order as the columns of expr (when it is a dataframe) and that contains the patient identifier of each sample.

TimePoint

a numeric vector or a factor of length p that is in the same order as Subject_ID and the columns of expr (when it is a dataframe), and that contains the time points at which gene expression was measured.

threshold

the threshold at which the FDR or the FWER should be controlled.

myproc

a vector of character strings containing the names of the multiple testing procedures for which adjusted p-values are to be computed. This vector should include any of the following: "Bonferroni", "Holm", "Hochberg", "SidakSS", "SidakSD", "BH", "BY", "ABH", "TSBH". See mt.rawp2adjp for details. Default is "BY", the Benjamini & Yekutieli (2001) step-up FDR-controlling procedure (general dependency structures). In order to control the FWER(in case of an analysis that is more a hypothesis confirmation than an exploration of the expression data), we recommend to use "Holm", the Holm (1979) step-down adjusted p-values for strong control of the FWER.

nbsimu_pval

the number of observations under the null distribution to be generated in order to compute the p-values. Default is 1e+06.

baseline

a character string which is the value of TimePoint that can be used as a baseline. Default is NULL, in which case no time point is used as a baseline value for gene expression. Has to be NULL when comparing several treatment groups.

only.signif

logical flag for analyzing the trends in only the significant gene sets. If FALSE, all the gene sets from the gmt object contained in x are clustered. Default is TRUE.

group.var

in the case of several treatment groups, this is a factor of length p that is in the same order as Timepoint, Subject_ID and the columns of expr. It indicates to which treatment group each sample belongs to. Default is NULL, which means that there is only one treatment group.

Group_ID_paired

a character vector of length p that is in the same order as Timepoint, Subject_ID, group.var and the columns of expr. This argument must not be NULL in the case of a paired analysis, and must be NULL otherwise. Default is NULL.

ref

the group which is used as reference in the case of several treatment groups. Default is NULL, which means that reference is the first group in alphabetical order of the labels of group.var.

group_of_interest

the group of interest, for which dynamics are to be computed in the case of several treatment groups. Default is NULL, which means that group of interest is the second group in alphabetical order of the labels of group.var.

FUNcluster

the clustering function used to agglomerate genes in trends. Default is NULL, in which a hierarchical clustering is performed via the function agnes , using the metric clustering_metric and the method clustering_method. See clusGap

clustering_metric

character string specifying the metric to be used for calculating dissimilarities between observations in the hierarchical clustering when FUNcluster is NULL. The currently available options are "euclidean" and "manhattan". Default is "euclidean". See agnes . Also, a "sts" option is available in TcGSA. It implements the 'Short Time Series' distance [Moller-Levet et al., Fuzzy Clustering of short time series and unevenly distributed sampling points, Advances in Intelligent Data Analysis V:330-340 Springer, 2003] designed specifically for clustering time series.

clustering_method

character string defining the agglomerative method to be used in the hierarchical clustering when FUNcluster is NULL. The six methods implemented are "average" ([unweighted pair-]group average method, UPGMA), "single" (single linkage), "complete" (complete linkage), "ward" (Ward's method), "weighted" (weighted average linkage). Default is "ward". See agnes .

B

integer specifying the number of Monte Carlo ("bootstrap") samples used to compute the gap statistics. Default is 500. See clusGap .

max_trends

integer specifying the maximum number of different clusters to be tested. Default is 4.

aggreg.fun

a character string such as "mean", "median" or the name of any other defined statistics function that returns a single numeric value. It specifies the function used to aggregate the observations before the clustering. Default is to median. Default is "median".

na.rm.aggreg

a logical flag indicating whether NA should be remove to prevent propagation through aggreg.fun. Can be useful to set to TRUE with unbalanced design as those will generate structural NAs in $Estimations. Default is TRUE.

trend.fun

a character string such as "mean", "median" or the name of any other function that returns a single numeric value. It specifies the function used to calculate the trends of the identified clustered. Default is to median.

methodOptiClust

character string indicating how the "optimal" number of clusters is computed from the gap statistics and their standard deviations. Possible values are "globalmax", "firstmax", "Tibs2001SEmax", "firstSEmax" and "globalSEmax". Default is "firstSEmax". See 'method' in clusGap , Details and Tibshirani et al., 2001 in References.

indiv

a character string indicating by which unit observations are aggregated (through aggreg.fun) before the clustering. Possible values are "genes" or "patients". Default is "genes".

verbose

logical flag enabling verbose messages to track the computing status of the function. Default is TRUE.

x

an object of class 'ClusteredTrends'.

...

further arguments passed to or from other methods.

Details

If expr is a matrix or a dataframe, then the genes dynamics are clustered on the "original" data. On the other hand, if expr is a list returned in the 'Estimations' element of TcGSA.LR , then the dynamics are computed on the estimations made by the TcGSA.LR function.

This function uses the Gap statistics to determine the optimal number of clusters in the plotted gene set. See clusGap .

Value

An object of class ClusteredTrends which is a list with the 4 following components:

NbClust a vector that contains the optimal number of clusters for each analyzed gene sets.
ClustsMeds a list of the same length as NsClust (the number of analyzed gene sets). Each element of the list is a data frame, in which there is as many column as the optimal number of clusters for the corresponding gene sets for each cluster. Each column of the data frame contains the median trend values for the corresponding cluster.
GenesPartition a list of the same length as NsClust (the number of analyzed gene sets). Each element of the list is a vector which gives the partition of the genes inside the corresponding gene set.
MaxNbClust an integer storing the maximum number of different clusters tested, as given by the argument 'max_trends'.

Author(s)

Boris P. Hejblum

References

Tibshirani, R., Walther, G. and Hastie, T., 2001, Estimating the number of data clusters via the Gap statistic, Journal of the Royal Statistical Society, Series B (Statistical Methodology), 63, 2: 41–423.

Examples


if(interactive()){
data(data_simu_TcGSA)
tcgsa_sim_1grp <- TcGSA.LR(expr=expr_1grp, gmt=gmt_sim, design=design, 
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=FALSE)
 
CT <- clustTrend(tcgsa_sim_1grp,
 expr=expr_1grp, Subject_ID=design$Subject_ID, TimePoint=design$TimePoint)
CT
plot(CT)
CT$NbClust
CT$NbClust["Gene set 5"]
CT$ClustMeds[["Gene set 4"]]
CT$ClustMeds[["Gene set 5"]]
}

Simulated Data for TcGSA

Description

Simulated data for 5 gene sets of 50 genes each. Gene expression is simulated at 5 time points for 10 patients.

Usage

data(data_simu_TcGSA)

Details

In expr_1grp all patients belong to the same unique treatment group. The first 2 gene sets are simulated under the null hypothesis. The gene sets 3 and 4 are simulated under the alternative hypothesis that there is a significant homogeneous time trend within the gene set. The gene set 5 is simulated under the alternative hypothesis that there are significant heterogeneous time trends within the gene set.

In expr_2grp all patients belong to 2 treatment groups. The 5 first patients belong to the treatment group 'T', The 5 other patients belong to the treatment group 'C'. The first 2 gene sets are simulated under the null hypothesis that there is no difference in the time trend between the 2 treatment groups. The gene sets 3 and 4 are simulated under the alternative hypothesis that there are significantly different homogeneous time trends within the gene set between the 2 treatment groups. The gene set 5 is simulated under the alternative hypothesis that there are significantly different heterogeneous time trends between the 2 treatment groups within the gene set.

Value

expr_1grp

See Details.

expr_2grp

See Details.

design

a data frame with 5 variables:

Patient_ID: a factor that contains the patient ID.
TimePoint: a numeric vector or a factor that contains the time points at which gene expression was measured.
sample_name: a character vector with the names of the sample (corresponding to the names of the columns of expr_1grp and of expr_2grp).
group.var: a factor that indicates to which of the 2 treatment groups each sample belongs to.
Group_paired_ID a random paired identifier for paired couples (one in each of the 2 treatment groups) of patients.

gmt_sim

a gmt object containing the gene sets definition. See GSA.read.gmt and GMT definition on https://docs.gsea-msigdb.org/.

Author(s)

Boris P. Hejblum

Source

This is simulated data.

Examples


data(data_simu_TcGSA)
summary(expr_1grp)
summary(design)
gmt_sim

Computing the P-value of the Likelihood Ratios Applying a Multiple Testing Correction

Description

This function computes the p-value of the likelihood ratios and apply a multiple testing correction.

Usage

multtest.TcGSA(
 tcgsa,
 threshold = 0.05,
 myproc = "BY",
 exact = TRUE,
 nbsimu_pval = 1e+06
)

Arguments

tcgsa

a TcGSA object.

threshold

the threshold at which the FDR or the FWER should be controlled.

myproc

a vector of character strings containing the names of the multiple testing procedures for which adjusted p-values are to be computed. This vector should include any of the following: "Bonferroni", "Holm", "Hochberg", "SidakSS", "SidakSD", "BH", "BY", "ABH", "TSBH" or "none". "none" indicates no adjustment for multiple testing. See mt.rawp2adjp for details. Default is "BY", the Benjamini & Yekutieli (2001) step-up FDR-controlling procedure (general dependency structures). In order to control the FWER (in case of an analysis that is more a hypothesis confirmation than an exploration of the expression data), we recommend to use "Holm", the Holm (1979) step-down adjusted p-values for strong control of the FWER.

exact

logical flag indicating whether the raw p-values should be computed from the exact asymptotic mixture of chi-square, or simulated (longer and not better). Default is TRUE and should be preferred.

nbsimu_pval

the number of observations under the null distribution to be generated in order to compute the p-values. Default is 1e+06.

Value

multtest.TcGSA returns an dataframe with 5 variables. The rows correspond to the gene sets under scrutiny. The 1st column is the likelihood ratios LR, the 2nd column is the convergence status of the model under the null hypothesis CVG_H0, the 3rd column is the convergence status of the model under the alternative hypothesis CVG_H1, the 4th column is the raw p-value of the mixed likelihood ratio test raw_pval, the 5th column is the adjusted p-value of the mixed likelihood ratio test adj_pval.

Author(s)

Boris P. Hejblum

Examples


if(interactive()){
data(data_simu_TcGSA)
tcgsa_sim_1grp <- TcGSA.LR(expr=expr_1grp, gmt=gmt_sim, design=design, 
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=FALSE)
 
mtt <- multtest.TcGSA(tcgsa_sim_1grp, threshold = 0.05, 
 myproc = "BY", nbsimu_pval = 1000)
mtt
}

Plot a Gene Set Trends Heatmap.

Description

This function plots a gene sets dynamic trends heatmap.

Usage

## S3 method for class 'TcGSA'
plot(
 x,
 threshold = 0.05,
 myproc = "BY",
 nbsimu_pval = 1e+06,
 expr,
 Subject_ID,
 TimePoint,
 baseline = NULL,
 only.signif = TRUE,
 group.var = NULL,
 Group_ID_paired = NULL,
 ref = NULL,
 group_of_interest = NULL,
 ranking = FALSE,
 FUNcluster = NULL,
 clustering_metric = "euclidian",
 clustering_method = "ward",
 B = 500,
 max_trends = 4,
 aggreg.fun = "median",
 na.rm.aggreg = TRUE,
 methodOptiClust = "firstSEmax",
 indiv = "genes",
 verbose = TRUE,
 clust_trends = NULL,
 N_clusters = NULL,
 myclusters = NULL,
 label.clusters = NULL,
 prev_rowCL = NULL,
 descript = TRUE,
 plot = TRUE,
 color.vec = c("darkred", "#D73027", "#FC8D59", "snow", "#91BFDB", "#4575B4",
 "darkblue"),
 legend.breaks = NULL,
 label.column = NULL,
 time_unit = "",
 cex.label.row = 1,
 cex.label.column = 1,
 margins = c(5, 25),
 heatKey.size = 1,
 dendrogram.size = 1,
 heatmap.height = 1,
 heatmap.width = 1,
 cex.clusterKey = 1,
 cex.main = 1,
 horiz.clusterKey = TRUE,
 main = NULL,
 subtitle = NULL,
 ...
)

Arguments

x

an object of class'TcGSA'.

threshold

the threshold at which the FDR or the FWER should be controlled.

myproc

a vector of character strings containing the names of the multiple testing procedures for which adjusted p-values are to be computed. This vector should include any of the following: "Bonferroni", "Holm", "Hochberg", "SidakSS", "SidakSD", "BH", "BY", "ABH", "TSBH" or "none". "none" indicates no adjustment for multiple testing. See mt.rawp2adjp for details. Default is "BY", the Benjamini & Yekutieli (2001) step-up FDR-controlling procedure (general dependency structures). In order to control the FWER(in case of an analysis that is more a hypothesis confirmation than an exploration of the expression data), we recommend to use "Holm", the Holm (1979) step-down adjusted p-values for strong control of the FWER.

nbsimu_pval

the number of observations under the null distribution to be generated in order to compute the p-values. Default is 1e+06.

expr

Subject_ID

a factor of length p that is in the same order as the columns of expr (when it is a dataframe) and that contains the patient identifier of each sample. Ignored if expr is a list of estimations.

TimePoint

baseline

the value of TimePoint to be used as baseline. Default is NULL in which case expression is centered and no baseline is used.

only.signif

logical flag for plotting only the significant gene sets. If FALSE, all the gene sets from the gmt object contained in x are plotted. Default is TRUE.

group.var

in the case of several treatment' groups, this is a factor of length p that is in the same order as Timepoint, Subject_ID, sample_name and the columns of expr. It indicates to which treatment group each sample belongs to. Default is NULL, which means that there is only one treatment group. See Details.

Group_ID_paired

a character vector of length p that is in the same order as Timepoint, Subject_ID, sample_name, group.var and the columns of expr. This argument must not be NULL in the case of a paired analysis, and must be NULL otherwise. Default is NULL. See Details.

ref

the group which is used as reference in the case of several treatment groups. Default is NULL, which means that reference is the first group in alphabetical order of the labels of group.var. See Details.

group_of_interest

ranking

a logical flag. If TRUE, the gene set trends are not hierarchically classified, but ordered by decreasing Likelihood ratios. Default is FALSE.

FUNcluster

clustering_metric

clustering_method

B

integer specifying the number of Monte Carlo ("bootstrap") samples used to compute the gap statistics. Default is 500. See clusGap .

max_trends

integer specifying the maximum number of different clusters to be tested. Default is 4.

aggreg.fun

a character string such as "mean", "median" or the name of any other statistics function defined that returns a single numeric value. It specifies the function used to aggregate the observations before the clustering. Default is to median. Default is "median".

na.rm.aggreg

methodOptiClust

character string indicating how the "optimal"" number of clusters is computed from the gap statistics and their standard deviations. Possible values are "globalmax", "firstmax", "Tibs2001SEmax", "firstSEmax" and "globalSEmax". Default is "firstSEmax". See 'method' in clusGap , Details and Tibshirani et al., 2001 in References.

indiv

a character string indicating by which unit observations are aggregated (through aggreg.fun) before the clustering. Possible values are "genes" or "patients". Default is "genes".

verbose

logical flag enabling verbose messages to track the computing status of the function. Default is TRUE.

clust_trends

object of class ClusteredTrends containing already computed trends for the plotted gene sets. Default is NULL.

N_clusters

an integer that is the number of clusters in which the dynamics should be regrouped. The cutoff of the clustering tree is automatically calculated accordingly. Default is NULL, in which case the dendrogram is not cut and no clusters are identified.

myclusters

a character vector of colors for predefined clusters of the represented gene sets, with as many levels as the value of N_clusters. Default is NULL, in which case the clusters are automatically identified and colored via the cutree function and the N_clusters argument only.

label.clusters

if N_clusters is not NULL, a character vector of length N_clusterss. Default is NULL, in which case if N_clusters is not NULL, clusters are simply labeled with numbers.

prev_rowCL

a hclust object, such as the one return by the present plotting function (see Value) for instance. If not NULL, no clustering is calculated by the present plotting function and this tree is used to represent the gene sets dynamics. Default is NULL.

descript

logical flag indicating that the description of the gene sets should appear after their name on the right side of the plot if TRUE. Default is TRUE. See Details.

plot

logical flag indicating whether the heatmap should be plotted or not. Default is TRUE.

color.vec

a character strings vector used to define the color palette used in the plot. Default is c("#D73027", "#FC8D59","lightyellow", "#91BFDB", "#4575B4").

legend.breaks

a numeric vector indicating the splitting points for coloring. Default is NULL, in which case the break points will be spaced equally and symmetrically about 0.

label.column

a vector of character strings with the labels to be displayed for the columns (i.e. the time points). Default is NULL.

time_unit

the time unit to be displayed (such as "Y", "M", "W", "D", "H", etc) next to the values of TimePoint in the columns labels when label.column is NULL. Default is "".

cex.label.row

a numerical value giving the amount by which row labels text should be magnified relative to the default 1.

cex.label.column

a numerical value giving the amount by which column labels text should be magnified relative to the default 1.

margins

numeric vector of length 2 containing the margins (see par(mar= *)) for column and row names, respectively. Default is c(15, 100). See Details.

heatKey.size

the size of the color key for the heatmap fill. Default is 1.

dendrogram.size

the horizontal size of the dendrogram. Default is 1

heatmap.height

the height of the heatmap. Default is 1

heatmap.width

the width of the heatmap. Default is 1

cex.clusterKey

a numerical value giving the amount by which the clusters legend text should be magnified relative to the default 1, when N_clusters is not NULL.

cex.main

a numerical value giving the amount by which title text should be magnified relative to the default 1.

horiz.clusterKey

a logical flag; if TRUE, set the legend for clusters horizontally rather than vertically. Only used if the N_clusters argument is not NULL. Default is TRUE.

main

a character string for an optional title. Default is NULL.

subtitle

a character string for an optional subtitle. Default is NULL.

...

other parameters to be passed through to plotting functions.

Details

On the heatmap, each line corresponds to a gene set, and each column to a time point.

If expr is a matrix or a dataframe, then the "original" data are plotted. On the other hand, if expr is a list returned in the 'Estimations' element of TcGSA.LR , then it is those "estimations" made by the TcGSA.LR function that are plotted.

If descript is FALSE, the second element of margins can be reduced (for instance use margins = c(5, 10)), as there is not so much need for space in order to display only the gene set names, without their description.

If there is a large number of significant gene sets, the hierarchical clustering step repeated for each of them can take a few minutes. To speed things up (especially) when playing with the plotting parameters for having a nice plot, one can run the clustTrend function beforehand, and plug its results in the plot.TcGSA function via the clust_trends argument.

Value

An object of class hclust which describes the tree produced by the clustering process. The object is a list with components:

merge an n-1 by 2 matrix. Row i of merge describes the merging of clusters at step i of the clustering. If an element j in the row is negative, then observation -j was merged at this stage. If j is positive then the merge was with the cluster formed at the (earlier) stage j of the algorithm. Thus negative entries in merge indicate agglomerations of singletons, and positive entries indicate agglomerations of non-singletons.
height a set of n-1 real values (non-decreasing for ultrametric trees). The clustering height: that is, the value of the criterion associated with the Ward clustering method.
order a vector giving the permutation of the original observations suitable for plotting, in the sense that a cluster plot using this ordering and matrix merge will not have crossings of the branches.
labels the gene set trends name.
call the call which produced the result clustering:
hclust(d = dist(map2heat, method = "euclidean"), method = "ward.D2")
method "ward.D2", as it is the clustering method that has been used for clustering the gene set trends.
dist.method "euclidean", as it is the distance that has been used for clustering the gene set trends.
legend.breaks a numeric vector giving the splitting points used for coloring the heatmap. If plot is FALSE, then it is NULL.
myclusters a character vector of colors for the dynamic clusters of the represented gene set trends, with as many levels as the value of N_clusters. If no dynamic clusters were represented, than this is NULL.
ddr a dendrogram object with the reordering used for the heatmap. See heatmap.2 function from package gplots.
gene set.names character vector with the names of the gene sets used in the heatmap.
clust.trends a ClusteredTrends object.
clustersExport a data frame with 2 variables containing the two following variables :
- GeneSet: the gene set trends clustered.
- Cluster: the dynamic cluster they belong to.
The data frame is order by the variable Cluster.
data_plotted: the data matrix represented by the heatmap

Author(s)

Boris P. Hejblum

References

Hejblum BP, Skinner J, Thiebaut R, (2015) Time-Course Gene Set Analysis for Longitudinal Gene Expression Data. PLOS Comput. Biol. 11(6): e1004310. doi: 10.1371/journal.pcbi.1004310

Examples


if(interactive()){
data(data_simu_TcGSA)
tcgsa_sim_1grp <- TcGSA.LR(expr=expr_1grp, gmt=gmt_sim, design=design, 
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=FALSE)
summary(tcgsa_sim_1grp)
plot(x=tcgsa_sim_1grp, expr=tcgsa_sim_1grp$Estimations, 
 Subject_ID=design$Patient_ID, TimePoint=design$TimePoint,
 baseline=1, 
 B=100,
 time_unit="H",
 dendrogram.size=0.4, heatmap.width=0.8, heatmap.height=2, cex.main=0.7
 )
 
tcgsa_sim_2grp <- TcGSA.LR(expr=expr_2grp, gmt=gmt_sim, design=design, 
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=FALSE, 
 group_name="group.var")
summary(tcgsa_sim_2grp) 
plot(x=tcgsa_sim_2grp, expr=expr_2grp, 
 Subject_ID=design$Patient_ID, TimePoint=design$TimePoint,
 B=100,
 time_unit="H",
 )
}

Plotting a Specific Gene Set

Description

This function can plot different representations of the gene expression in a specific gene set.

Usage

plot1GS(
 expr,
 gmt,
 Subject_ID,
 TimePoint,
 geneset.name,
 baseline = NULL,
 group.var = NULL,
 Group_ID_paired = NULL,
 ref = NULL,
 group_of_interest = NULL,
 FUNcluster = NULL,
 clustering_metric = "euclidian",
 clustering_method = "ward",
 B = 500,
 max_trends = 4,
 aggreg.fun = "median",
 na.rm.aggreg = TRUE,
 trend.fun = "median",
 methodOptiClust = "firstSEmax",
 indiv = "genes",
 verbose = TRUE,
 clustering = TRUE,
 showTrend = TRUE,
 smooth = TRUE,
 precluster = NULL,
 time_unit = "",
 title = NULL,
 y.lab = NULL,
 desc = TRUE,
 lab.cex = 1,
 axis.cex = 1,
 main.cex = 1,
 y.lab.angle = 90,
 x.axis.angle = 45,
 margins = 1,
 line.size = 1,
 y.lim = NULL,
 x.lim = NULL,
 gg.add = list(theme()),
 plot = TRUE
)

Arguments

expr

gmt

a gmt object containing the gene sets definition. See GSA.read.gmt and https://docs.gsea-msigdb.org/.

Subject_ID

a factor of length p that is in the same order as the columns of expr (when it is a dataframe) and that contains the patient identifier of each sample.

TimePoint

geneset.name

a character string containing the name of the gene set to be plotted, that must appear in the "geneset.names" element of gmt.

baseline

group.var

Group_ID_paired

ref

group_of_interest

FUNcluster

a function which accepts as first argument a matrix x and as second argument the number of clusters desired k, and which returns a list with a component named 'cluster' which is a vector of length n = nrow(x) of integers in 1:k, determining the clustering or grouping of the n observations. Default is NULL, in which case a hierarchical clustering is performed via the function agnes , using the metric clustering_metric and the method clustering_method. See 'FUNcluster' in clusGap and Details.

clustering_metric

clustering_method

B

integer specifying the number of Monte Carlo ("bootstrap") samples used to compute the gap statistics. Default is 500. See clusGap .

max_trends

integer specifying the maximum number of different clusters to be tested. Default is 4.

aggreg.fun

a character string such as "median" or "mean" or the name of any other defined statistics function that returns a single numeric value. It specifies the function used to aggregate the observations before the clustering. Default is to "mean".

na.rm.aggreg

trend.fun

a character string such as "mean" or the name of any other function that returns a single numeric value. It specifies the function used to calculate the trends of the identified clustered. Default is to "mean".

methodOptiClust

indiv

a character string indicating by which unit observations are aggregated (through aggreg.fun) before the clustering. Possible values are "genes" or "patients". Default is "genes". See Details.

verbose

logical flag enabling verbose messages to track the computing status of the function. Default is TRUE.

clustering

logical flag. If FALSE, there is no clustering representation; if TRUE, the lines are colored according to which cluster they belong to. Default is TRUE. See Details.

showTrend

logical flag. If TRUE, a black line is added for each cluster, representing the corresponding trend.fun. Default is TRUE.

smooth

logical flag. If TRUE and showTrend is also TRUE, the representation of each cluster trend.fun is smoothed using cubic polynomials (see geom_smooth . Default is TRUE. At the moment, must accept parameter "na.rm" (which is automatically set to TRUE). This might change in future versions

precluster

a vector of length p that is in the same order as Subject_ID, TimePoint and the columns of expr (when it is a dataframe), and that contains a prior clustering of the subjects. Default is NULL.

time_unit

the time unit to be displayed (such as "Y", "M", "W", "D", "H", etc) next to the values of TimePoint on the x-axis. Default is "", in which case the time scale on the x-axis is proportional to the time values.

title

character specifying the title of the plot. If NULL, a title is automatically generated, if "", no title appears. Default is NULL.

y.lab

character specifying the annotation of the y axis. If NULL, an annotation is automatically generated, if "", no annotation appears. Default is NULL.

desc

a logical flag. If TRUE, a line is added to the title of the plot with the description of the gene set plotted (from the gmt file). Default is TRUE.

lab.cex

a numerical value giving the amount by which lab labels text should be magnified relative to the default 1.

axis.cex

a numerical value giving the amount by which axis annotation text should be magnified relative to the default 1.

main.cex

a numerical value giving the amount by which title text should be magnified relative to the default 1.

y.lab.angle

a numerical value (in [0, 360]) giving the orientation by which y-label text should be turned (anti-clockwise). Default is 90. See element_text .

x.axis.angle

a numerical value (in [0, 360]) giving the orientation by which x-axis annotation text should be turned (anti-clockwise). Default is 45.

margins

a numerical value giving the amount by which the margins should be reduced or increased relative to the default 1.

line.size

a numerical value giving the amount by which the line sizes should be reduced or increased relative to the default 1.

y.lim

a numeric vector of length 2 giving the range of the y-axis. See plot.default .

x.lim

if numeric, will create a continuous scale, if factor or character, will create a discrete scale. Observations not in this range will be dropped. See xlim .

gg.add

A list of instructions to add to the ggplot2 instructions. See +.gg . Default is list(theme()), which adds nothing to the plot.

plot

logical flag. If FALSE, no plot is drawn. Default is TRUE.

Details

If indiv is 'genes', then each line of the plot is the median of a gene expression over the patients. On the other hand, if indiv is 'patients', then each line of the plot is the median of a patient genes expression in this gene set.

This function uses the Gap statistics to determine the optimal number of clusters in the plotted gene set. See clusGap .

Value

A list with 2 elements:

classif: a data.frame with the 2 following variables: ProbeID which contains the IDs of the probes of the plotted gene set, and Cluster containing $ which cluster the probe belongs to. If clustering is FALSE, then Cluster is NA for all the probes.
p: a ggplot object containing the plot

Author(s)

Boris P. Hejblum

References

Examples


if(interactive()){
data(data_simu_TcGSA)
tcgsa_sim_1grp <- TcGSA.LR(expr=expr_1grp, gmt=gmt_sim, design=design, 
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=FALSE)
plot1GS(expr=expr_1grp, TimePoint=design$TimePoint, 
 Subject_ID=design$Patient_ID, gmt=gmt_sim,
 geneset.name="Gene set 4",
 indiv="genes", clustering=FALSE,
 time_unit="H",
 lab.cex=0.7)
plot1GS(expr=expr_1grp, TimePoint=design$TimePoint, 
 Subject_ID=design$Patient_ID, gmt=gmt_sim,
 geneset.name="Gene set 5",
 indiv="patients", clustering=FALSE, baseline=1,
 time_unit="H",
 lab.cex=0.7)
}
if(interactive()){ 
geneclusters <- plot1GS(expr=tcgsa_sim_1grp$Estimations, TimePoint=design$TimePoint, 
 Subject_ID=design$Patient_ID, gmt=gmt_sim,
 geneset.name="Gene set 5",
 indiv="genes",
 time_unit="H",
 lab.cex=0.7
)
geneclusters
}
if(interactive()){
library(grDevices)
library(graphics)
colval <- c(hsv(0.56, 0.9, 1),
 hsv(0, 0.27, 1),
 hsv(0.52, 1, 0.5),
 hsv(0, 0.55, 0.97),
 hsv(0.66, 0.15, 1),
 hsv(0, 0.81, 0.55),
 hsv(0.7, 1, 0.7),
 hsv(0.42, 0.33, 1)
)
n <- length(colval); y <- 1:n
op <- par(mar=rep(1.5,4))
plot(y, axes = FALSE, frame.plot = TRUE,
	 xlab = "", ylab = "", pch = 21, cex = 8,
	 bg = colval, ylim=c(-1,n+1), xlim=c(-1,n+1),
	 main = "Color scale"
)
par(op)
plot1GS(expr=expr_1grp, TimePoint=design$TimePoint, 
 Subject_ID=design$Patient_ID, gmt=gmt_sim,
 geneset.name="Gene set 5",
 indiv="genes",
 time_unit="H",
 title="",
 gg.add=list(scale_color_manual(values=colval), 
 guides(colour = guide_legend(reverse=TRUE))),
 lab.cex=0.7
)
plot1GS(expr=expr_2grp, TimePoint=design$TimePoint, 
 Subject_ID=design$Patient_ID, gmt=gmt_sim,
 geneset.name="Gene set 3",
 indiv="genes",
 group.var = design$group.var,
 time_unit="H",
 gg.add=list(scale_color_manual(values=colval), 
 guides(colour = guide_legend(reverse=TRUE))),
 lab.cex=0.7
)
}

Plotting function for exploring the fitness of the mixed modeling used in TcGSA

Description

This function plots graphs informing on the fit of the mixed modeling of the gene expression performed in TcGSA, for 1 or several gene sets.

Usage

plotFit.GS(
 x,
 expr,
 design,
 subject_name = "Patient_ID",
 time_name = "TimePoint",
 colnames_ID,
 plot_type = c("Fit", "Residuals Obs", "Residuals Est", "Histogram Obs"),
 GeneSetsList,
 color = c("genes", "time", "subjects"),
 marginal_hist = TRUE,
 gg.add = list(theme())
)

Arguments

x

a tcgsa object for clustTrend, or a ClusteredTrends object for print.ClusteredTrends and plot.ClusteredTrends.

expr

a matrix or dataframe of gene expression. Its dimension are nxp, with the p samples in column and the n genes in row.

design

subject_name

time_name

the name of a numeric variable from design that contains the information on the time replicates (the time points at which gene expression was measured). Default is 'TimePoint'. See Details.

colnames_ID

the name of the variable from design that contains the column names of the expr expression data matrix. See Details.

plot_type

a character string indicating the type of plot to be drawn. The options are 'Fit', 'Residuals Obs', 'Residuals Est' or 'Histogram Obs'.

GeneSetsList

a character string containing the names of the gene set whose fit is being checked. If several gene sets are being checked, can be a character list or vector of the names of those gene sets.

color

a character string indicating which color scale should be used. One of the 3 : 'genes', 'time', 'subjects', otherwise, no coloring is used.

marginal_hist

a logical flag indicating whether marginal histograms should be drawn. Only used for 'Fit' plot type. Default is 'TRUE'

gg.add

A list of instructions to add to the ggplot2 instructions. See +.gg . Default is list(theme()), which adds nothing to the plot.

Author(s)

Boris P. Hejblum

References

Hejblum BP, Skinner J, Thiebaut R, (2015) Time-Course Gene Set Analysis for Longitudinal Gene Expression Data. PLOS Comput. Biol. 11(6):e1004310. doi: 10.1371/journal.pcbi.1004310

Examples


if(interactive()){
data(data_simu_TcGSA)
tcgsa_sim_1grp <- TcGSA.LR(expr=expr_1grp, gmt=gmt_sim, design=design, 
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=FALSE)
plotFit.GS(x=tcgsa_sim_1grp, expr=expr_1grp, design=design,
				 subject_name="Patient_ID", time_name="TimePoint",
				 colnames_ID="Sample_name", 
				 plot_type="Residuals Obs", 
				 GeneSetsList=c("Gene set 1", "Gene set 2", "Gene set 3",
				 "Gene set 4", "Gene set 5"),
				 color="genes", gg.add=list(guides(color=FALSE))
)
plotFit.GS(x=tcgsa_sim_1grp, expr=expr_1grp, design=design,
 subject_name="Patient_ID", time_name="TimePoint",
 colnames_ID="Sample_name", 
 plot_type="Histogram Obs", 
 GeneSetsList=c("Gene set 1", "Gene set 5"),
 color="genes", gg.add=list(guides(fill=FALSE))
 )
 
plotFit.GS(x=tcgsa_sim_1grp, expr=expr_1grp, design=design,
 subject_name="Patient_ID", time_name="TimePoint",
 colnames_ID="Sample_name", 
 plot_type="Histogram Obs", 
 GeneSetsList=c("Gene set 1", "Gene set 2", "Gene set 3",
		 "Gene set 4", "Gene set 5"),
 color="genes")
}

Plotting Multiple Gene Sets in a single plot

Description

This function can plot different representations of the gene expression in a list of gene sets.

Usage

plotMultipleGS(
 genesets_list,
 ncolumns = 1,
 labels = NULL,
 expr,
 gmt,
 Subject_ID,
 TimePoint,
 baseline = NULL,
 group.var = NULL,
 Group_ID_paired = NULL,
 ref = NULL,
 group_of_interest = NULL,
 FUNcluster = NULL,
 clustering_metric = "euclidian",
 clustering_method = "ward",
 B = 500,
 max_trends = 4,
 aggreg.fun = "median",
 na.rm.aggreg = TRUE,
 trend.fun = "median",
 methodOptiClust = "firstSEmax",
 indiv = "genes",
 verbose = TRUE,
 clustering = TRUE,
 showTrend = TRUE,
 smooth = TRUE,
 time_unit = "",
 y.lab = NULL,
 desc = TRUE,
 lab.cex = 1,
 axis.cex = 1,
 main.cex = 1,
 y.lab.angle = 90,
 x.axis.angle = 45,
 margins = 1,
 line.size = 1,
 y.lim = NULL,
 x.lim = NULL,
 gg.add = list(),
 show_plot = TRUE
)

Arguments

genesets_list

a list of the character strings giving the names of the gene sets to be plotted as they appear in gmt.

ncolumns

the number of columns used to display the multiple plots. Default is 1.

labels

List of labels to be added to the plots. You can also set labels="AUTO" to auto-generate upper-case labels (such as A, B, ...) or labels="auto" to auto-generate lower-case labels. Default is NULL

expr

gmt

a gmt object containing the gene sets definition. See GSA.read.gmt and https://docs.gsea-msigdb.org/.

Subject_ID

a factor of length p that is in the same order as the columns of expr (when it is a dataframe) and that contains the patient identifier of each sample.

TimePoint

baseline

group.var

Group_ID_paired

ref

group_of_interest

FUNcluster

clustering_metric

clustering_method

B

integer specifying the number of Monte Carlo ("bootstrap") samples used to compute the gap statistics. Default is 500. See clusGap .

max_trends

integer specifying the maximum number of different clusters to be tested. Default is 4.

aggreg.fun

na.rm.aggreg

trend.fun

methodOptiClust

indiv

a character string indicating by which unit observations are aggregated (through aggreg.fun) before the clustering. Possible values are "genes" or "patients". Default is "genes". See Details.

verbose

logical flag enabling verbose messages to track the computing status of the function. Default is TRUE.

clustering

logical flag. If FALSE, there is no clustering representation; if TRUE, the lines are colored according to which cluster they belong to. Default is TRUE. See Details.

showTrend

logical flag. If TRUE, a black line is added for each cluster, representing the corresponding trend.fun. Default is TRUE.

smooth

time_unit

y.lab

character specifying the annotation of the y axis. If NULL, an annotation is automatically generated, if "", no annotation appears. Default is NULL.

desc

a logical flag. If TRUE, a line is added to the title of the plot with the description of the gene set plotted (from the gmt file). Default is TRUE.

lab.cex

a numerical value giving the amount by which lab labels text should be magnified relative to the default 1.

axis.cex

a numerical value giving the amount by which axis annotation text should be magnified relative to the default 1.

main.cex

a numerical value giving the amount by which title text should be magnified relative to the default 1.

y.lab.angle

a numerical value (in [0, 360]) giving the orientation by which y-label text should be turned (anti-clockwise). Default is 90. See element_text .

x.axis.angle

a numerical value (in [0, 360]) giving the orientation by which x-axis annotation text should be turned (anti-clockwise). Default is 45.

margins

a numerical value giving the amount by which the margins should be reduced or increased relative to the default 1.

line.size

a numerical value giving the amount by which the line sizes should be reduced or increased relative to the default 1.

y.lim

a numeric vector of length 2 giving the range of the y-axis. See plot.default .

x.lim

if numeric, will create a continuous scale, if factor or character, will create a discrete scale. Observations not in this range will be dropped. See xlim .

gg.add

A list of instructions to add to the ggplot2 instructions. See +.gg . Default is list(theme()), which adds nothing to the plot.

show_plot

logical flag. If FALSE, no plot is drawn. Default is TRUE.

Details

This function uses the Gap statistics to determine the optimal number of clusters in the plotted gene set. See clusGap .

Value

A list with 2 elements:

classif: a data.frame with the 2 following variables: ProbeID which contains the IDs of the probes of the plotted gene set, and Cluster containing $ which cluster the probe belongs to. If clustering is FALSE, then Cluster is NA for all the probes.
p: a ggplot object containing the plot

Author(s)

Boris P. Hejblum

Plotting a Specific Gene Set Stratifying on Patients

Description

This function can plot different representations of the gene expression in a specific gene set, stratified on all subjects.

Usage

plotPat.1GS(
 expr,
 gmt,
 Subject_ID,
 TimePoint,
 geneset.name,
 baseline = NULL,
 group.var = NULL,
 Group_ID_paired = NULL,
 ref = NULL,
 group_of_interest = NULL,
 FUNcluster = NULL,
 clustering_metric = "euclidian",
 clustering_method = "ward",
 B = 500,
 max_trends = 4,
 aggreg.fun = "median",
 na.rm.aggreg = TRUE,
 trend.fun = "median",
 methodOptiClust = "firstSEmax",
 verbose = TRUE,
 clustering = TRUE,
 time_unit = "",
 title = NULL,
 y.lab = NULL,
 desc = TRUE,
 lab.cex = 1,
 axis.cex = 1,
 main.cex = 1,
 y.lab.angle = 90,
 x.axis.angle = 45,
 y.lim = NULL,
 x.lim = NULL,
 gg.add = list(theme())
)

Arguments

expr

gmt

a gmt object containing the gene sets definition. See GSA.read.gmt and https://docs.gsea-msigdb.org/.

Subject_ID

a factor of length p that is in the same order as the columns of expr (when it is a dataframe) and that contains the patient identifier of each sample.

TimePoint

a numeric vector or a factor of length p that is in the same order as TimePoint and the columns of expr (when it is a dataframe), and that contains the time points at which gene expression was measured.

geneset.name

a character string containing the name of the gene set to be plotted, that must appear in the "geneset.names" element of gmt.

baseline

group.var

Group_ID_paired

ref

group_of_interest

FUNcluster

clustering_metric

clustering_method

B

integer specifying the number of Monte Carlo ("bootstrap") samples used to compute the gap statistics. Default is 500. See clusGap .

max_trends

integer specifying the maximum number of different clusters to be tested. Default is 4.

aggreg.fun

na.rm.aggreg

trend.fun

methodOptiClust

verbose

logical flag enabling verbose messages to track the computing status of the function. Default is TRUE.

clustering

logical flag. If FALSE, there is no clustering representation; if TRUE, the lines are colored according to which cluster they belong to. Default is TRUE. See Details.

time_unit

the time unit to be displayed (such as "Y", "M", "W", "D", "H", etc) next to the values of TimePoint on the x-axis. Default is "".

title

character specifying the title of the plot. If NULL, a title is automatically generated, if "", no title appears. Default is NULL.

y.lab

character specifying the annotation of the y axis. If NULL, an annotation is automatically generated, if "", no annotation appears. Default is NULL.

desc

a logical flag. If TRUE, a line is added to the title of the plot with the description of the gene set plotted (from the gmt file). Default is TRUE.

lab.cex

a numerical value giving the amount by which lab labels text should be magnified relative to the default 1.

axis.cex

a numerical value giving the amount by which axis annotation text should be magnified relative to the default 1.

main.cex

a numerical value giving the amount by which title text should be magnified relative to the default 1.

y.lab.angle

a numerical value (in [0, 360]) giving the orientation by which y-label text should be turned (anti-clockwise). Default is 90. See element_text .

x.axis.angle

a numerical value (in [0, 360]) giving the orientation by which x-axis annotation text should be turned (anti-clockwise). Default is 45.

y.lim

a numeric vector of length 2 giving the range of the y-axis. See plot.default .

x.lim

if numeric, will create a continuous scale, if factor or character, will create a discrete scale. Observations not in this range will be dropped. See xlim .

gg.add

A list of instructions to add to the ggplot2 instructions. See +.gg . Default is list(theme()), which adds nothing to the plot.

Details

This function uses the Gap statistics to determine the optimal number of clusters in the plotted gene set. See clusGap .

Value

A dataframe the 2 following variables:

ProbeID which contains the IDs of the probes of the plotted gene set.
Cluster which to which cluster the probe belongs to.

If clustering is FALSE, then Cluster is NA for all the probes.

Author(s)

Boris P. Hejblum

References

Examples


if(interactive()){
data(data_simu_TcGSA)
tcgsa_sim_1grp <- TcGSA.LR(expr=expr_1grp, gmt=gmt_sim, design=design, 
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=FALSE)
plotPat.1GS(expr=expr_1grp, TimePoint=design$TimePoint, 
 Subject_ID=design$Patient_ID, gmt=gmt_sim,
 geneset.name="Gene set 4",
 clustering=FALSE,
 time_unit="H",
 lab.cex=0.7)
plotPat.1GS(expr=expr_1grp, TimePoint=design$TimePoint, 
 Subject_ID=design$Patient_ID, gmt=gmt_sim,
 geneset.name="Gene set 4",
 clustering=FALSE, baseline=1,
 time_unit="H",
 lab.cex=0.7)
 
colval <- c(hsv(0.56, 0.9, 1),
 hsv(0, 0.27, 1),
 hsv(0.52, 1, 0.5),
 hsv(0, 0.55, 0.97),
 hsv(0.66, 0.15, 1),
 hsv(0, 0.81, 0.55),
 hsv(0.7, 1, 0.7),
 hsv(0.42, 0.33, 1)
)
n <- length(colval); y <- 1:n
op <- par(mar=rep(1.5,4))
plot(y, axes = FALSE, frame.plot = TRUE,
	 xlab = "", ylab = "", pch = 21, cex = 8,
	 bg = colval, ylim=c(-1,n+1), xlim=c(-1,n+1),
	 main = "Color scale"
)
par(op)
plotPat.1GS(expr=expr_1grp, TimePoint=design$TimePoint, 
 Subject_ID=design$Patient_ID, gmt=gmt_sim,
 geneset.name="Gene set 5",
 time_unit="H",
 title="",
 gg.add=list(scale_color_manual(values=colval)),
 lab.cex=0.7
)
plotPat.1GS(expr=tcgsa_sim_1grp$Estimations, TimePoint=design$TimePoint, 
 Subject_ID=design$Patient_ID, gmt=gmt_sim,
 geneset.name="Gene set 3",
 time_unit="H",
 lab.cex=0.7
)
}

Plot a Gene Set Trends Heatmap for each Patient.

Description

This function plots a series of gene sets dynamic trends heatmaps. One heatmap is drawn for each patient. NOT IMPLEMENTED YET (TODO)

Usage

plotPat.TcGSA(
 x,
 threshold = 0.05,
 myproc = "BY",
 nbsimu_pval = 1e+06,
 expr,
 Subject_ID,
 TimePoint,
 baseline = NULL,
 only.signif = TRUE,
 group.var = NULL,
 Group_ID_paired = NULL,
 ref = NULL,
 group_of_interest = NULL,
 FUNcluster = NULL,
 clustering_metric = "euclidian",
 clustering_method = "ward",
 B = 500,
 max_trends = 4,
 aggreg.fun = "median",
 na.rm.aggreg = TRUE,
 methodOptiClust = "firstSEmax",
 verbose = TRUE,
 clust_trends = NULL,
 N_clusters = NULL,
 myclusters = NULL,
 label.clusters = NULL,
 prev_rowCL = NULL,
 descript = TRUE,
 plotAll = TRUE,
 color.vec = c("darkred", "#D73027", "#FC8D59", "snow", "#91BFDB", "#4575B4",
 "darkblue"),
 legend.breaks = NULL,
 label.column = NULL,
 time_unit = "",
 cex.label.row = 1,
 cex.label.column = 1,
 margins = c(5, 25),
 heatKey.size = 1,
 dendrogram.size = 1,
 heatmap.height = 1,
 heatmap.width = 1,
 cex.clusterKey = 1,
 cex.main = 1,
 horiz.clusterKey = TRUE,
 main = NULL,
 subtitle = NULL,
 ...
)

Arguments

x

a tcgsa object.

threshold

the threshold at which the FDR or the FWER should be controlled.

myproc

a vector of character strings containing the names of the multiple testing procedures for which adjusted p-values are to be computed. This vector should include any of the following: "Bonferroni", "Holm", "Hochberg", "SidakSS", "SidakSD", "BH", "BY", "ABH", "TSBH" or "none". "none" indicates no adjustment for multiple testing. See mt.rawp2adjp for details. Default is "BY", the Benjamini & Yekutieli (2001) step-up FDR-controlling procedure (general dependency structures). In order to control the FWER(in case of an analysis that is more a hypothesis confirmation than an exploration of the expression data), we recommend to use "Holm", the Holm (1979) step-down adjusted p-values for strong control of the FWER.

nbsimu_pval

the number of observations under the null distribution to be generated in order to compute the p-values. Default is 1e+06.

expr

Subject_ID

a factor of length p that is in the same order as the columns of expr (when it is a dataframe) and that contains the patient identifier of each sample.

TimePoint

baseline

a character string which is the value of TimePoint used as baseline.

only.signif

logical flag for plotting only the significant gene sets. If FALSE, all the gene sets from the gmt object contained in x are plotted. Default is TRUE.

group.var

in the case of several treatment groups, this is a factor of length p that is in the same order as Timepoint, Subject_ID, sample_name and the columns of expr. It indicates to which treatment group each sample belongs to. Default is NULL, which means that there is only one treatment group. See Details.

Group_ID_paired

ref

group_of_interest

FUNcluster

clustering_metric

clustering_method

B

integer specifying the number of Monte Carlo ("bootstrap") samples used to compute the gap statistics. Default is 500. See clusGap .

max_trends

integer specifying the maximum number of different clusters to be tested. Default is 4.

aggreg.fun

na.rm.aggreg

methodOptiClust

verbose

logical flag enabling verbose messages to track the computing status of the function. Default is TRUE.

clust_trends

object of class ClusteredTrends containing already computed trends for the plotted gene sets. Default is NULL.

N_clusters

myclusters

label.clusters

if N_clusters is not NULL, a character vector of length N_clusterss. Default is NULL, in which case if N_clusters is not NULL, clusters are simply labeled with numbers.

prev_rowCL

descript

logical flag indicating that the description of the gene sets should appear after their name on the right side of the plot if TRUE. Default is TRUE. See Details.

plotAll

logical flag indicating whether a first heatmap with the median over all the patients should be plotted, or not. Default is TRUE.

color.vec

a character strings vector used to define the color palette used in the plot. Default is c("#D73027", "#FC8D59","lightyellow", "#91BFDB", "#4575B4").

legend.breaks

a numeric vector indicating the splitting points for coloring. Default is NULL, in which case the break points will be spaced equally and symmetrically about 0.

label.column

a vector of character strings with the labels to be displayed for the columns (i.e. the time points). Default is NULL.

time_unit

the time unit to be displayed (such as "Y", "M", "W", "D", "H", etc) next to the values of TimePoint in the columns labels when label.column is NULL. Default is "".

cex.label.row

a numerical value giving the amount by which row labels text should be magnified relative to the default 1.

cex.label.column

a numerical value giving the amount by which column labels text should be magnified relative to the default 1.

margins

numeric vector of length 2 containing the margins (see par(mar= *)) for column and row names, respectively. Default is c(15, 100). See Details.

heatKey.size

the size of the color key for the heatmap fill. Default is 1.

dendrogram.size

the horizontal size of the dendrogram. Default is 1

heatmap.height

the height of the heatmap. Default is 1

heatmap.width

the width of the heatmap. Default is 1

cex.clusterKey

a numerical value giving the amount by which the clusters legend text should be magnified relative to the default 1, when N_clusters is not NULL.

cex.main

a numerical value giving the amount by which title text should be magnified relative to the default 1.

horiz.clusterKey

a logical flag; if TRUE, set the legend for clusters horizontally rather than vertically. Only used if the N_clusters argument is not NULL. Default is TRUE.

main

a character string for an optional title. Default is NULL.

subtitle

a character string for an optional subtitle. Default is NULL.

...

other parameters to be passed through to plotting functions.

Details

On the heatmap, each line corresponds to a gene set, and each column to a time point.

First a heatmap is computed on all the patients (see plot.TcGSA and clustTrend ) to define the clustering. Then, the clustering and coloring thus defined on all the patients are consistently used in the separate heatmaps that are plotted by patient.

The median shown in the heatmap uses the respectively standardized (reduced and centered) expression of the genes over the patients.

Value

An object of class hclust which describes the tree produced by the clustering process. The object is a list with components:

merge an n-1 by 2 matrix. Row i of merge describes the merging of clusters at step i of the clustering. If an element j in the row is negative, then observation -j was merged at this stage. If j is positive then the merge was with the cluster formed at the (earlier) stage j of the algorithm. Thus negative entries in merge indicate agglomerations of singletons, and positive entries indicate agglomerations of non-singletons.
height a set of n-1 real values (non-decreasing for ultrametric trees). The clustering height: that is, the value of the criterion associated with the Ward clustering method.
order a vector giving the permutation of the original observations suitable for plotting, in the sense that a cluster plot using this ordering and matrix merge will not have crossings of the branches.
labels the gene sets name.
call the call which produced the result clustering:
hclust(d = dist(map2heat, method = "euclidean"), method = "ward.D2")
method "ward.D2", as it is the clustering method that has been used for clustering the gene set trends.
dist.method "euclidean", as it is the distance that has been used for clustering the gene set trends.
legend.breaks a numeric vector giving the splitting points used for coloring the heatmap. If plot is FALSE, then it is NULL.
myclusters a character vector of colors for clusters of the represented gene sets, with as many levels as the value of N_clusters. If no clusters were represented, than this is NULL.
ddr a dendrogram object with the reordering used for the heatmap. See heatmap.2 function from package gplots.
clustersExport a data frame with 2 variables containing the two following variables :
- GeneSet: the gene sets clustered.
- Cluster: the cluster they belong to.
The data frame is order by the variable Cluster.

Author(s)

Boris P. Hejblum

References

Hejblum BP, Skinner J, Thiebaut R, (2015) Time-Course Gene Set Analysis for Longitudinal Gene Expression Data. PLOS Comput. Biol. 11(6):e1004310. doi: 10.1371/journal.pcbi.1004310

Examples


if(interactive()){
data(data_simu_TcGSA)
tcgsa_sim_1grp <- TcGSA.LR(expr=expr_1grp, gmt=gmt_sim, design=design, 
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=FALSE)
plotPat.TcGSA(x=tcgsa_sim_1grp, expr=expr_1grp, 
 Subject_ID=design$Patient_ID, TimePoint=design$TimePoint,
 B=100,
 time_unit="H"
 )
plotPat.TcGSA(x=tcgsa_sim_1grp, expr=tcgsa_sim_1grp$Estimations, 
 Subject_ID=design$Patient_ID, TimePoint=design$TimePoint,
 baseline=1, 
 B=100,
 time_unit="H"
 )
}

Plotting (several) Selected Gene Set(s) in some Subjects

Description

This function can plot different representations of the gene expression in selected gene sets, among a subset of selected subjects.

Usage

plotSelect.GS(
 expr,
 gmt,
 Subject_ID,
 TimePoint,
 geneset.names.select,
 Subject_ID.select,
 display = "one subject per page",
 baseline = NULL,
 group.var = NULL,
 Group_ID_paired = NULL,
 ref = NULL,
 group_of_interest = NULL,
 FUNcluster = NULL,
 clustering_metric = "euclidian",
 clustering_method = "ward",
 B = 500,
 max_trends = 4,
 aggreg.fun = "median",
 na.rm.aggreg = TRUE,
 trend.fun = "median",
 methodOptiClust = "firstSEmax",
 verbose = TRUE,
 clustering = TRUE,
 time_unit = "",
 title = NULL,
 y.lab = NULL,
 desc = TRUE,
 lab.cex = 1,
 axis.cex = 1,
 main.cex = 1,
 y.lab.angle = 90,
 x.axis.angle = 45,
 y.lim = NULL,
 x.lim = NULL,
 gg.add = list(theme())
)

Arguments

expr

gmt

a gmt object containing the gene sets definition. See GSA.read.gmt and https://docs.gsea-msigdb.org/.

Subject_ID

a factor of length p that is in the same order as the columns of expr (when it is a dataframe) and that contains the patient identifier of each sample.

TimePoint

geneset.names.select

a character vector containing the names of the gene sets to be plotted, that must appear in the "geneset.names" element of gmt.

Subject_ID.select

a character vector containing the names of the subjects to be plotted, that must appear in the Subject_ID vector.

display

How to display the resulting graphs. One of the following : "one GS per page", "one subject per page", "median over selected patients". Default is "one subject per page".

baseline

group.var

Group_ID_paired

ref

group_of_interest

FUNcluster

clustering_metric

clustering_method

B

integer specifying the number of Monte Carlo ("bootstrap") samples used to compute the gap statistics. Default is 500. See clusGap .

max_trends

integer specifying the maximum number of different clusters to be tested. Default is 4.

aggreg.fun

na.rm.aggreg

trend.fun

methodOptiClust

verbose

logical flag enabling verbose messages to track the computing status of the function. Default is TRUE.

clustering

logical flag. If FALSE, there is no clustering representation; if TRUE, the lines are colored according to which cluster they belong to. Default is TRUE. See Details.

time_unit

the time unit to be displayed (such as "Y", "M", "W", "D", "H", etc) next to the values of TimePoint on the x-axis. Default is "".

title

character specifying the title of the plot. If NULL, a title is automatically generated, if "", no title appears. Default is NULL.

y.lab

character specifying the annotation of the y axis. If NULL, an annotation is automatically generated, if "", no annotation appears. Default is NULL.

desc

a logical flag. If TRUE, a line is added to the title of the plot with the description of the gene set plotted (from the gmt file). Default is TRUE.

lab.cex

a numerical value giving the amount by which lab labels text should be magnified relative to the default 1.

axis.cex

a numerical value giving the amount by which axis annotation text should be magnified relative to the default 1.

main.cex

a numerical value giving the amount by which title text should be magnified relative to the default 1.

y.lab.angle

a numerical value (in [0, 360]) giving the orientation by which y-label text should be turned (anti-clockwise). Default is 90. See element_text .

x.axis.angle

a numerical value (in [0, 360]) giving the orientation by which x-axis annotation text should be turned (anti-clockwise). Default is 45.

y.lim

a numeric vector of length 2 giving the range of the y-axis. See plot.default .

x.lim

if numeric, will create a continuous scale, if factor or character, will create a discrete scale. Observations not in this range will be dropped. See xlim .

gg.add

A list of instructions to add to the ggplot2 instructions. See +.gg . Default is list(theme()), which adds nothing to the plot.

Details

This function uses the Gap statistics to determine the optimal number of clusters in the plotted gene set. See clusGap .

Value

A dataframe the 2 following variables:

ProbeID which contains the IDs of the probes of the plotted gene set.
Cluster which to which cluster the probe belongs to.

If clustering is FALSE, then Cluster is NA for all the probes.

Author(s)

Boris P. Hejblum

References

Examples


if(interactive()){
data(data_simu_TcGSA)
tcgsa_sim_1grp <- TcGSA.LR(expr=expr_1grp, gmt=gmt_sim, design=design, 
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=TRUE)
}
if(interactive()){
plotSelect.GS(expr=expr_1grp, TimePoint=design$TimePoint, 
 Subject_ID=design$Patient_ID, gmt=gmt_sim,
 geneset.names.select=c("Gene set 4", "Gene set 5"),
 Subject_ID.select=c("P1", "P2"),
 display="one GS per page", 
 time_unit="H",
 lab.cex=0.7
)
}
if(interactive()){
plotSelect.GS(expr=tcgsa_sim_1grp$Estimations, TimePoint=design$TimePoint, 
 Subject_ID=design$Patient_ID, gmt=gmt_sim,
 geneset.names.select=c("Gene set 4", "Gene set 5"),
 Subject_ID.select=c("P1", "P2"),
 display="one subject per page", 
 time_unit="H",
 lab.cex=0.7
)
}
if(interactive()){
tcgsa_sim_1grp <- TcGSA.LR(expr=expr_1grp, gmt=gmt_sim, design=design, 
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=FALSE)
 
plotSelect.GS(expr=tcgsa_sim_1grp$Estimations, TimePoint=design$TimePoint, 
 Subject_ID=design$Patient_ID, gmt=gmt_sim,
 geneset.names.select=c("Gene set 4", "Gene set 5"),
 Subject_ID.select=c("P1", "P2"),
 display="one subject per page", 
 time_unit="H",
 lab.cex=0.7
)
}

Computing P-values with a Simulated Sample from the Null Distribution

Description

This function computes the p-value of a statistic using a simulated sample from its theoretical null distribution.

Usage

pval_simu(s, theo_dist)

Arguments

s

the observation whose p-value is computed. For instance a Likelihood Ratio.

theo_dist

the sample of the distribution under the null hypothesis.

Value

The p-value associated to the observation s.

Author(s)

Boris P. Hejblum

Examples


if(interactive()){
theo_dist <- rnorm(n=10000, mean=0, sd=1)
TcGSA:::pval_simu(s=1.96, theo_dist)
1-pnorm(q=1.96, mean = 0, sd = 1, lower.tail = TRUE, log.p = FALSE)
}

Chi-Squared Mixtures Distribution

Description

Density, distribution function, quantile function and random generation for mixtures of chi-squared distributions that corresponds to the null distribution of the Likelihood Ratio between 2 nested mixed models.

Usage

rchisqmix(n, s, q)
dchisqmix(x, s, q)
qchisqmix(p, s, q)
pchisqmix(quant, s, q, lower.tail = TRUE)

Arguments

n

number of observations.

s

number of fixed effects to be tested.

q

number of random effects to be tested.

x, quant

a quantile.

p

a probability.

lower.tail

logical; if TRUE (default), probabilities are P[X \le x]; otherwise, P[X > x].

Details

The approximate null distribution of a likelihood ratio for 2 nested mixed models, where both fixed and random effects are tested simultaneously, is a very specific mixture of \chi^2 distributions [Self & Liang (1987), Stram & Lee (1994) and Stram & Lee (1995)]. It depends on both the number of random effects and the number of fixed effects to be tested simultaneously:

LRT_{H_0}\sim\sum_{k=q}^{q+r}{{r}\choose{k-q}}2^{-r}\chi^2_{(k)}

Value

A vector of random independent observations of the \chi^2 mixture identified by the values of s and q.

Author(s)

Boris P. Hejblum

References

Self, S. G. and Liang, K., 1987, Asymptotic properties of maximum likelihood estimators and likelihood ratio tests under nonstandard conditions, Journal of the American Statistical Association 82: 605–610.

Stram, D. O. and Lee, J. W., 1994, Variance components testing in the longitudinal mixed effects model, Biometrics 50: 1171–1177.

Stram, D. O. and Lee, J. W., 1995, Corrections to "Variance components testing in the longitudinal mixed effects model" by Stram, D. O. and Lee, J. W.; 50: 1171–1177 (1994), Biometrics 51: 1196.

Examples

library(graphics)
library(stats)
sample_mixt <- rchisqmix(n=1000, s=3, q=3)
plot(density(sample_mixt))

Identifying the Significant Gene Sets

Description

A function that identifies the significant gene sets in an object of class 'TcGSA'.

Usage

signifLRT.TcGSA(
 tcgsa,
 threshold = 0.05,
 myproc = "BY",
 nbsimu_pval = 1e+06,
 write = F,
 txtfilename = NULL,
 directory = NULL,
 exact = TRUE
)

Arguments

tcgsa

a tcgsa object.

threshold

the threshold at which the FDR or the FWER should be controlled.

myproc

a vector of character strings containing the names of the multiple testing procedures for which adjusted p-values are to be computed. This vector should include any of the following: "Bonferroni", "Holm", "Hochberg", "SidakSS", "SidakSD", "BH", "BY", "ABH", "TSBH" or "none". "none" indicates no adjustment for multiple testing. See mt.rawp2adjp for details. Default is "BY", the Benjamini & Yekutieli (2001) step-up FDR-controlling procedure (general dependency structures). In order to control the FWER(in case of an analysis that is more a hypothesis confirmation than an exploration of the expression data), we recommend to use "Holm", the Holm (1979) step-down adjusted p-values for strong control of the FWER.

nbsimu_pval

the number of observations under the null distribution to be generated in order to compute the p-values. Default is 1e+06.

write

logical flag enabling the export of the results as a table in a .txt file. Default is FALSE.

txtfilename

a character string with the name of the .txt file in which the results table is to be written, if write is TRUE. Default is NULL.

directory

if write is TRUE, a character string with the directory of the .txt file in which the results table is to be written, if write is TRUE. Default is NULL.

exact

logical flag indicating whether the raw p-values should be computed from the exact asymptotic mixture of chi-square, or simulated (longer and not better). Default is TRUE and should be preferred.

Value

signifLRT.TcGSA returns a list.

The first element mixedLRTadjRes is data frame with p rows (one row for each significant gene set) and the 3 following variables:

GeneSet the significant gene set name from the gmt object.
AdjPval the adjusted p-value corresponding to the significant gene set.
desc the significant gene set description from the gmt object.

The second element multCorProc passes along the multiple testing procedure used (from the argument myproc).

The third element threshold passes along the significance threshold used (from the argument threshold).

Author(s)

Boris P. Hejblum

References

Hejblum BP, Skinner J, Thiebaut R, (2015) Time-Course Gene Set Analysis for Longitudinal Gene Expression Data. PLOS Comput. Biol. 11(6):e1004310. doi: 10.1371/journal.pcbi.1004310

Examples

if(interactive()){
data(data_simu_TcGSA)
tcgsa_sim_1grp <- TcGSA.LR(expr=expr_1grp, gmt=gmt_sim, design=design, 
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=FALSE)
 
sgnifs <- signifLRT.TcGSA(tcgsa_sim_1grp, threshold = 0.05, myproc = "BY",
 nbsimu_pval = 1000, write=FALSE)
sgnifs
}

Summarizing TcGSA

Description

summary method for class 'TcGSA'

Usage

## S3 method for class 'TcGSA'
summary(object, ...)
## S3 method for class 'summary.TcGSA'
print(x, ...)

Arguments

object

an object of class 'TcGSA'.

...

further arguments passed to or from other methods.

x

an object of class 'summary.TcGSA'.

Value

The function summary.TcGSA returns a list with the following components (list elements):

time_func the chosen form for the time trend.
separateSubjects a logical flag indicating whether gene sets tested for discriminating among patients, or for time trends over time.
ntg the number of treatment groups.
ngs the number of tested gene sets.
nsignif the number of significant gene sets at a 5% FDR (using the default Benjamini & Yekutieli step-up procedure).

Author(s)

Boris P. Hejblum

Examples


if(interactive()){
data(data_simu_TcGSA)
tcgsa_sim_1grp <- TcGSA.LR(expr=expr_1grp, gmt=gmt_sim, design=design, 
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=FALSE)
summary(tcgsa_sim_1grp)
tcgsa_sim_2grp <- TcGSA.LR(expr=expr_2grp, gmt=gmt_sim, design=design, 
 subject_name="Patient_ID", time_name="TimePoint",
 time_func="linear", crossedRandom=FALSE, 
 group_name="group.var")
summary(tcgsa_sim_2grp)
}

Time-course Gene Set Analysis

Description

Details

Author(s)

References

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Internal TcGSA Functions

Description

Details

Computing the Likelihood Ratios for the Gene Sets under Scrutiny

Description

Usage

Arguments

Details

Value

Author(s)

References

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Examples

Parallel computing the Likelihood Ratios for the Gene Sets under Scrutiny

Description

Usage

Arguments

Details

Value

Author(s)

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Examples

Cluster the genes dynamics into different dominant trends.

Description

Usage

Arguments

Details

Value

Author(s)

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Examples

Simulated Data for TcGSA

Description

Usage

Details

Value

Author(s)

Source

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Examples

Computing the P-value of the Likelihood Ratios Applying a Multiple Testing Correction

Description

Usage

Arguments

Value

Author(s)

See Also

Examples

Plot a Gene Set Trends Heatmap.

Description

Usage

Arguments

Details

Value

Author(s)

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Examples

Plotting a Specific Gene Set

Description

Usage

Arguments

Details

Value

Author(s)

References

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Examples

Plotting function for exploring the fitness of the mixed modeling used in TcGSA

Description

Usage

Arguments