nctcdf (Statistics Toolbox)

Noncentral T cumulative distribution function.

Syntax

P = nctcdf(X,NU,DELTA)

Description

P = nctcdf(X,NU,DELTA) returns the noncentral T cdf with NU degrees of freedom and noncentrality parameter, DELTA, at the values in X.

The size of P 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 cdf with DELTA = 1 to the T cdf with the same number of degrees of freedom (10).

x = (-5:0.1:5)';
p1 = nctcdf(x,10,1);
p = tcdf(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.