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tstat - Student's t mean and variance

Syntax

[M,V] = tstat(NU)

Description

[M,V] = tstat(NU) returns the mean of and variance for Student's t distribution using the degrees of freedom in NU. M and V are the same size as NU.

The mean of the Student's t distribution with parameter ν is zero for values of ν greater than 1. If ν is one, the mean does not exist. The variance for values of ν greater than 2 is .

Examples

Find the mean of and variance for 1 to 30 degrees of freedom.

[m,v] = tstat(reshape(1:30,6,5))
m =
  NaN  0   0   0   0
   0   0   0   0   0
   0   0   0   0   0
   0   0   0   0   0
   0   0   0   0   0
   0   0   0   0   0

v =
    NaN   1.4000  1.1818  1.1176  1.0870
    NaN   1.3333  1.1667  1.1111  1.0833
  3.0000  1.2857  1.1538  1.1053  1.0800
  2.0000  1.2500  1.1429  1.1000  1.0769
  1.6667  1.2222  1.1333  1.0952  1.0741
  1.5000  1.2000  1.1250  1.0909  1.0714

Note that the variance does not exist for one and two degrees of freedom.

See Also

tpdf, tcdf, tinv, trnd

trnd

ttest

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