T_PDF

The T_PDF function computes the probability P that, in a Student's t distribution with Df degrees of freedom, a random variable X is less than or equal to a user-specified cutoff value V .

This routine is written in the IDL language. Its source code can be found in the file t_pdf.pro in the lib subdirectory of the IDL distribution.

Calling Sequence

Result = T_PDF( V, Df )

Arguments

V

An integer, single-, or double-precision floating-point scalar that specifies the cutoff value.

Df

A positive integer, single- or double-precision floating-point scalar that specifies the number of degrees of freedom of the Student's t distribution.

Example

Use the following command to compute the probability that a random variable X, from the Student's t distribution with 15 degrees of freedom, is less than or equal to 0.691. The result should be 0.749940.

result = T_PDF(0.691, 15)

PRINT, result

IDL prints:

0.749940

See Also

BINOMIAL , CHISQR_PDF , F_PDF , GAUSS_PDF , T_CVF