NominalVariables
is an option for statistical functions such as LinearModelFit that specifies which variables should be treated as having discrete values specified by names.
Details
- Possible settings for NominalVariables include:
-
Automatic automaticaly detect nominal variablesAll treat all variables as nominalNone treat no variables as nominal{v1,v2,…} treat the variables vi as nominal
- When NominalVariables->Automatic , different methods are used to detect nominal variables. In functions returning FittedModel […], variables with non-numeric data values are treated as nominal.
- In linear models, a nominal variable v with possible values s1, s2, … is represented as a collection of variables with values 1 or 0 corresponding to each case v==si.
Examples
open allclose allBasic Examples (1)
Define some data:
Fit the data, treating the first variable as a nominal variable:
See the functional form:
Treat all variables as nominal:
Scope (2)
Automatically select nominal variables:
Specify nominal variables in GeneralizedLinearModelFit :
With LogitModelFit :
With ProbitModelFit :
Applications (3)
Fit a one‐way ANOVA model:
Obtain the ANOVA table:
Compute the model estimates for the three groups:
Fit a two‐way ANOVA model with interaction term:
Obtain the ANOVA table:
Compute estimates for each cell:
Results in a table:
Fit an ANCOVA model:
Visualize curves for the three x categories and label using Tooltip :
Related Guides
Text
Wolfram Research (2008), NominalVariables, Wolfram Language function, https://reference.wolfram.com/language/ref/NominalVariables.html (updated 2014).
CMS
Wolfram Language. 2008. "NominalVariables." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2014. https://reference.wolfram.com/language/ref/NominalVariables.html.
APA
Wolfram Language. (2008). NominalVariables. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/NominalVariables.html
BibTeX
@misc{reference.wolfram_2025_nominalvariables, author="Wolfram Research", title="{NominalVariables}", year="2014", howpublished="\url{https://reference.wolfram.com/language/ref/NominalVariables.html}", note=[Accessed: 17-April-2025 ]}
BibLaTeX
@online{reference.wolfram_2025_nominalvariables, organization={Wolfram Research}, title={NominalVariables}, year={2014}, url={https://reference.wolfram.com/language/ref/NominalVariables.html}, note=[Accessed: 17-April-2025 ]}