hi all, i have been using the function for the pdf of the dirichlet distribution in GSL (through a python interface.)
the function works correctly on most values, but appears to return nan when it shouldn't on more extreme cases. for example, the pdf evaluated on the set of values [0, 0, 1] with parameter settings [1/3, 1/3, 1/3] returns NaN, even though [0, 0, 1] is a perfectly fine value for the dirichlet pdf that should have non-zero probability. this is true for both the dirichlet_pdf and dirichlet_lnpdf (log of pdf) functions. in python notation, this is: dirichlet_pdf([0, 0, 1], [1/3., 1/3., 1/3.]) (evaluates to NaN) dirichlet_lnpdf([0, 0, 1], [1/3., 1/3., 1/3.]) (evaluates to NaN as well) any idea why this is or how i can fix it? thank you. _______________________________________________ Help-gsl mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-gsl
