[Boost-users] Boost_1_54_0: boost::math::sph_bessel(n, x) crash at x=0 n>0

17 Oct 2013

      Dear developpers,

I'am running Boost 1_54_0 on Scientific Linux  slc-6.1,  gcc-4.4.5, 64 
bits machine.

I face a problem with computation of spherical bessel function, although 
the problem seems well known here
is a test program

   {
     int L;
     try {
       for(L=100;L<2010;L++) {
     boost::math::sph_bessel(L, 0.);
       }
     } catch (std::exception& sex) {
       cout << "Error j_"<<L<<"(0): "<< sex.what() << endl;
     }
   }

And the output
Error j_1755(0): Error in function boost::math::tgamma<e>(e): Result of 
tgamma is too large to represent.

which tends to point out that at L=1755 the spherical bessel function 
get a problem once one ant to estimate at x=0.

Of course, I know that j0(0) = 1 and for L>0 jL(0) = 0 but 1) I'm using 
a program which compute integral of product of bessel function
and sometimes it needs to call the function at 0. So I would expect the 
BOOST library to be protected against that.

Am I wrong?

Best regards
Jean-Eric

[Boost-users] Boost_1_54_0: boost::math::sph_bessel(n, x) crash at x=0 n>0

JE Campagne