Dear all, I wonder if someone can illuminate me on numerical integration with PDL. I have tried (almost) hard with both chia (PDL::Slatec) and gslinteg_qng (PDL::GSL::INTEG) but got a bit swamped.
Essentially, I have two piddles coming from the output of "hist": one contains xvals and the other the frequencies. What I need to do is to calculate the integral of that histogram over different intervals . My actual code looks like this (using GSL): use PDL; use PDL::GSL::INTEG; my $xmin = min $a; # the minimum limit of integration my $xmax = max $glacier; # maximum limit my $s_ave = avg $s; # some value extracted from another piddle my $epsrel = 0; # this value is taken from the example in the documentation my $epsabs = 1e-3; # same as above, but a bit higher my ($a1,$abserr,$ierr,$neval); # define variables # try to integrate. $b is a 1-D piddle containing the ($a1,$abserr,$ierr,$neval) = gslinteg_qng( $b, $zmin, $s_ave, $epsrel,$epsabs); Then I get this: Not a CODE reference at /usr/lib/perl5/site_perl/5.10.0/x86_64-linux-thread-multi/PDL/GSL/INTEG.pm line 589. May be there is a problem because I did not define a certain subroutine &myfunc, but the fact is that I do not have a function in the traditional sense, but two list of values, one representing the independent variable and the other the (unknown) function values. Any hint will be appreciated, Thanks in advance Hernán -- Hernán De Angelis Linux user # 397217 _______________________________________________ Perldl mailing list [email protected] http://mailman.jach.hawaii.edu/mailman/listinfo/perldl
