lyngby_cdf_t

 lyngby_cdf_t         - Student t distribution

       function P = lyngby_cdf_t(x,r)

       Input:  x   Value where the function is evaluated
               r   Degrees of freedom

       Output: P   Lower tail area

       Lower tail (cumulated) Student t distribution.

       This function uses an approximation to the t distribution. The
       approximation cannot be used for all values of x and r. For
       the case where the approximation cannot be used the t
       distribution is computed via the incomplete Beta function.

        Ref: Lennart Raade, Beta, 17.4, page 385
            Press, Numerical Recipes, sec 6.4

       See also LYNGBY, LYNGBY_IDF_T, LYNGBY_CDF_F,
                LYNGBY_CDF_GAUSS.

 $Id: lyngby_cdf_t.m,v 1.4 2003/02/11 19:55:54 fnielsen Exp $