Problems with integration when wrapping it for Python.

[Vanroose Wim <vanroose at ruca dot ua dot ac dot be>]

Dear Sir, Madam,

    I am new  to GSL discuss list.
    I recently started to use the GSL library to do calculations in
physics.  Previously I used a collection of fortran function that I
f2c'd to use in C++, python and C.   So I am very happy with the GSL
library, It makes my life easier.
     I used the integration package to do some integrations in C. The
program works fine and gives very accurate results. My pure C program
was based on the example included in the on-line manual.
     But when I tried to wrap the function that calculates the integral
into a "shared library" to be used by python. the troubles start. I
seems that as soon as I  allocate the memory with
"gsl_integration_workspace" my application crashes.
    Does anybody has the same experiences.


    I include some code snippets of the  example,  When I eleminate the
integration application in "calculate" and just return a number it works
fine but as soon I allocate the workspace the problems start


##############################################################################

double calculate( double oscillatorL, int n,int m){
  double output,error;
  gsl_integration_workspace * w = gsl_integration_workspace_alloc(1000);

  gsl_function F;
  struct integration_params  p;
  F.function = &integrationformula;
  F.params = &p;
  p.n=n;
  p.m=m;
  p.b=oscillatorL;
  gsl_integration_qag(&F, 0, 30, 0, 1e-5, 1000, 4,w, &output, &error);
  return  output;
}


static PyObject *  matrix(PyObject *self, PyObject *args){
  double oscillatorL;
  if(!PyArg_ParseTuple(args,"d",&oscillatorL)
    return NULL;
  return Py_BuildValue("f",calculate(oscillatorL,1,1));
}

static PyMethodDef potentialMethods[] = {
  {"matrix",matrix,1},
  {"wim",wim,1},
  {NULL,NULL}
};

void initpotential(){
  PyObject *m, *d;
  m = Py_InitModule("potential", potentialMethods);
  import_array();
  d = PyModule_GetDict(m);
}

#############################################################################

MakeFile

potential: potential.c
    gcc -c -fpic potential  -I$(PYTHONINCL) -I$(GSLINCLUDE)
    gcc -shared -fpic -o potentialmodule.sl potential.o -L(GSLLIB)
-lgslspecfunc -lgslerr -lgslintegration -lm