nctpdf (Statistics Toolbox)

Noncentral T probability density function (pdf).

Syntax

Y = nctpdf(X,V,DELTA)

Description

Y = nctpdf(X,V,DELTA) returns the noncentral T pdf with V degrees of freedom and noncentrality parameter, DELTA, at the values in X.

The size of Y is the common size of the input arguments. A scalar input functions as a constant matrix of the same size as the other inputs.

Example

Compare the noncentral T pdf with DELTA = 1 to the T pdf with the same number of degrees of freedom (10).

x = (-5:0.1:5)';
p1 = nctpdf(x,10,1);
p = tpdf(x,10);
plot(x,p,'- -',x,p1,'-')

References

Evans, M., N. Hastings, and B. Peacock, Statistical Distributions, Second Edition, John Wiley and Sons, 1993. p. 147-148.

Johnson, N., and S. Kotz, Distributions in Statistics: Continuous Univariate Distributions-2, John Wiley and Sons, 1970. pp. 201-219.