Close
Close window
Cumulant - Maple Help
For the best experience, we recommend viewing online help using Google Chrome or Mozilla Firefox.
Maplesoft logo
Maplesoft logo

Online Help

All Products Maple MapleSim


[フレーム] [フレーム]

Statistics

Cumulant

compute cumulants

Calling Sequence

Cumulant(A, n, ds_options)

Cumulant(M, n, ds_options)

Cumulant(X, n, rv_options)

Parameters

X

-

algebraic; random variable or distribution

n

-

algebraic; order

ds_options

-

(optional) equation(s) of the form option=value where option is one of ignore, or weights; specify options for computing the cumulant of a data set

rv_options

-

(optional) equation of the form numeric=value; specifies options for computing the cumulant of a random variable

Description

The Cumulant function computes the cumulant of order n of the specified random variable or data set.

The first parameter can be a data set (e.g., a Vector ), a Matrix data set , a distribution (see Statistics[Distribution] ), a random variable, or an algebraic expression involving random variables (see Statistics[RandomVariable] ).

The second parameter can be any Maple expression.

Computation

All computations involving data are performed in floating-point; therefore, all data provided must have type realcons and all returned solutions are floating-point, even if the problem is specified with exact values.

By default, all computations involving random variables are performed symbolically (see option numeric below).

For more information about computation in the Statistics package, see the Statistics[Computation] help page.

Data Set Options

The ds_options argument can contain one or more of the options shown below. More information for some options is available in the Statistics[DescriptiveStatistics] help page.

ignore=truefalse -- This option controls how missing data is handled by the Cumulant command. Missing items are represented by undefined or Float(undefined). So, if ignore=false and A contains missing data, the Cumulant command will return undefined. If ignore=true all missing items in A will be ignored. The default value is false.

weights=Vector -- Data weights. The number of elements in the weights array must be equal to the number of elements in the original data sample. By default all elements in A are assigned weight 1.

Random Variable Options

The rv_options argument can contain one or more of the options shown below. More information for some options is available in the Statistics[RandomVariables] help page.

numeric=truefalse -- By default, the cumulant is computed symbolically. To compute the cumulant numerically, specify the numeric or numeric = true option.

Examples

>

withStatistics:

Compute the third cumulant of the beta distribution with parameters 3 and 5.

>

CumulantΒ3,5,3

1768

(1)
>

CumulantΒ3,5,3,numeric

0.001302083333

(2)

Generate a random sample of size 100000 drawn from the above distribution and compute the third cumulant.

>

ASampleΒ3,5,105:

>

CumulantA,3

0.00134022023133534

(3)

Create a beta-distributed random variable Y and compute the third cumulant of 1/(Y+2).

>

YRandomVariableΒ5,2:

>

Cumulant1Y+2,3,numeric

0.00001053303

(4)

Verify this using simulation.

>

CSample1Y+2,105:

>

CumulantC,3

0.0000106158294638642

(5)

Compute the cumulant of a weighted data set.

>

Vseqi,i=57..77,undefined:

>

W2,4,14,41,83,169,394,669,990,1223,1329,1230,1063,646,392,202,79,32,16,5,2,5:

>

CumulantV,4,weights=W

Floatundefined

(6)
>

CumulantV,4,weights=W,ignore=true

6.34287269040942

(7)

Consider the following Matrix data set .

>

MMatrix3,1130,114694,4,1527,127368,3,907,88464,2,878,96484,4,995,128007

M31130114694415271273683907884642878964844995128007

(8)

We compute the second cumulant of each column.

>

CumulantM,2

0.55999999999999955998.63999999972.57876120640001×108

(9)

References

Stuart, Alan, and Ord, Keith. Kendall's Advanced Theory of Statistics. 6th ed. London: Edward Arnold, 1998. Vol. 1: Distribution Theory.

Compatibility

The M parameter was introduced in Maple 16.

For more information on Maple 16 changes, see Updates in Maple 16 .


Download Help Document

AltStyle によって変換されたページ (->オリジナル) /