nag_log_beta (s14cbc) calculates values for
where
is the beta function given by
or equivalently
and
is the gamma function. Note that the beta function is symmetric, so that
.
In order to efficiently obtain accurate results several methods are used depending on the parameters and .
nag_log_beta (s14cbc) is derived from BETALN in
DiDonato and Morris (1992).
DiDonato A R and Morris A H (1992) Algorithm 708: Significant digit computation of the incomplete beta function ratios ACM Trans. Math. Software 18 360–373
nag_log_beta (s14cbc) should produce full relative accuracy for all input arguments.
Not applicable.
None.