[ctypes-users] Problems with c_double pointer

[Antti <ant...@he...>]

Hi everybody!

I'm having some problems calling a C DLL from python. I have two almost=20
similar functions in the DLL, that I'm calling. The otherone works just=20
fine and the other doesn't.

This is the first function (C header):
int Diameter_distribution_pine_Weibull_Mykkanen ( double BA, double DgM,=20
double DIAM_CLASS_WIDTH, double max_class_count, int *nres, struct=20
diamclass *dist, char *warnings, char *errors) ;

The struct is my own struct that contains two doubles. The last for=20
arguments are pointers, because the DLL sets values for the arguments and=
 I=20
use those values in the python later on.

This is the second function:
double Height_pine_Veltheim (double d, double Age, double BA, double DgM,=
=20
double TS, double ALT, int SC, int *nres, double *modelresult, char=20
*warnings, char *errors);

The only difference to the first function is the 3rd last=20
argument 'modelresult'.

When i call the functions from python, i use c_int and byref() fro the=20
integer pointer, (c_double * 60)() for my own struct and=20
create_string_buffer for the char pointers.

This way the first function works and I can get proper values from the=20
pointer arguments. The second function gives "WindowsError: exception:=20
access violation writing 0x40080000" when I try to execute it on WingIDE.

Am I missing something here or what?

-Antti M=E4kinen