[Bug-gsl] [bug #28500] overflow in gsl_ran_fdist_pdf

[Brian Gough]

URL:
  <http://savannah.gnu.org/bugs/?28500>

                 Summary: overflow in gsl_ran_fdist_pdf
                 Project: GNU Scientific Library
            Submitted by: bjg
            Submitted on: Wed 06 Jan 2010 05:55:17 PM GMT
                Category: Runtime error
                Severity: 3 - Normal
        Operating System: 
                  Status: Confirmed
             Assigned to: None
             Open/Closed: Open
                 Release: 1.13
         Discussion Lock: Any

    _______________________________________________________

Details:

From: Gunjan Verma <address@hidden>
To: address@hidden
Subject: [Bug-gsl] possible bug in F distribution computation
function        gsl_ran_fdist_pdf
Date: Tue, 5 Jan 2010 14:55:19 -0500

Dear GSL Community,
    Ran into a mysterious problem.

When I run gsl_ran_fdist_pdf(.012, 8, 249) I get infinity.
But when I run

gsl_ran_fdist_pdf(.012, 8, 248) I get .000074, which is correct (checked
against MATLAB and R)

one d.f. change makes this difference - but I don't see why it should from
the formula for F pdf.

i am running a Dell Latitude E6500 machine with ubuntu 9 linux , 64 bit and
gcc 4.4.1   . I built the gsl library from source for my system.


#include <gsl/gsl_randist.h>
#include <stdio.h>

int main ()
{
  double x = gsl_ran_fdist_pdf(.012,8,249);
  printf("%g\n", x);
}

=>

inf




    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/bugs/?28500>

_______________________________________________
  Message sent via/by Savannah
  http://savannah.gnu.org/