[Bug-gsl] gsl_cdf_beta_Pinv gives wrong result

[Sebastian Queißer]

Hi!

I'm using the GSL library version 1.9 (Debian package libgsl0-1.9-3).

It seems to me that gsl_cdf_beta_Pinv yields strange results:

gsl_cdf_beta_P(0.2053056, 2133, 10000 - 2133 + 1)
result: 0.0249996 (this is correct)

gsl_cdf_beta_Pinv(0.025, 2133, 10000 - 2133 + 1)
result: 0.172583 (the correct result should be 0.2053056)

gsl_cdf_beta_P(0.172583, 2133, 10000 - 2133 + 1)
result: 6.43881e-26 (this is correct and illustrates the problem)

I've attached a small test programm. You can compile it with
g++ -lgsl -lgslcblas test.cpp

I hope you'll be able to reproduce the problem.

Kind regards,
Sebastian Queißer

test.cpp
Description: Text Data