I don't see anywhere in your code where you create a variable in histforce_ips[0]. E.g.,
mxArray * histforce_ips[1];
:
mexCallMATLAB(1,histforce_ops,1,histforce_ips,"calchistforce");
There is nothing inbetween these lines that sets histforce_ips[0] to anything, so when you call mexCallMATLAB you are passing an invalid pointer for the input argument. You need to do something like this instead:
mxArray * histforce_ips[1];
:
histforce_ips[0] = mxCreateDoubleMatrix(mrows,ncols,mxREAL);
:
// Then fill in the values of histforce_ips[0] via mxGetPr etc
:
mexCallMATLAB(1,histforce_ops,1,histforce_ips,"calchistforce");
:
mxDestroyArray(histforce_ips[0]);
mxDestroyArray(histforce_ops[0]);
Also, I don't know if this will eventually make a difference in your code at some point, but the way you allocate your "a" and "b" matrices piecemeal means that the memory for them is not guaranteed to be contiguous. Generally, if you want to preserve the a[j][i] syntax of indexing I would recommend allocating a single block of memory and work with that instead. E.g.,
// allocate memory:
a=(double**)malloc(mrows*sizeof(double *));
b=(double**)malloc(mrows*sizeof(double *));
a[0] = (double *) malloc(mrows*ncols*sizeof(double));
b[0] = (double *) malloc(mrows*ncols*sizeof(double));
for(i=1;i<mrows;i++){
a[i] = a[i-1] + ncols;
b[i] = b[i-1] + ncols;
}
:
free(a[0]); free(a);
free(b[0]); free(b);
