cdft_t

Calculates the t-value given the one-sided probability and the degrees of freedom.

Prototype

	function cdft_t (
		p   : numeric,  
		df  : numeric   
	)

	return_val  :  numeric

Arguments

A scalar or array containing probabilities ( 0 <= p < 1 ).

A scalar or array of the same size as p containing the number of degrees of freedom.

Return value

A array of the same size as p. Double if any of the input arguments are double, float otherwise.

Description

Using the cumulative distribution function for the T distribution, calculate the t-values associated with one or more probabilities and degrees of freedom. Technically, this is the upper limit of integration of the t-density distribution.

The source code is from source routine "CDFT" from DCDFLIB (Double precision Cumulative Distribution Function LIBrary).

See Also

cdft_p

Examples

Example 1

     df = 16 

     p  = 0.025
     T = cdft_t(p, df)    ; T = -2.12

     p  = 0.975
     T = cdft_t(p, df)    ; T =  2.12