[Swig-user] Multi-dimensional arrays, C and pyhton

[Eric B. P. <ebp...@gm...>]

Please forgive me if this has been coerved before...but I am completely 
confused...

I am trying to understand the best/easiest/any way to hand a n x 3 
list/array of coordinates (X,Y,Z) to an existing C routine that wants 
the imput as double **.

After looking into NumPY, Cython, NumPy.i, swig etc and not being much 
of a C programmer, I am completely lost.

The C program stores data in a very complex typedef structure in a 
seperate module so I have written a basic method to take a 2D array and 
populate the structre, but can't figure out what I need to do to get the 
data from Python into my method.

I tried defining an interface using numpy.i in an swig interface file as 
follows:

%module pyTIN
%{
#define SWIG_FILE_WITH_INIT
#include <pyTIN.h>
%}

%include "numpy.i"

%init %{
import_array();
%}

%apply(double **IN_ARRAY2, int){(double **dataarray, int num_points)};
%include "pyTIN.h"
extern void createTIN(double**, int);


With the heard file (pyTIN.h) containing:

#include "tinlib.h"
double dataarray[500][2];

extern void createTIN(double **dataarray, int num_points);

void save_triangleSQL(FILE *outfile,PListT *points,intdex pdex0,intdex 
pdex1,intdex pdex2);

void tin_save_trianglesSQL(tin_contextT *tcontext,char *filename);

which seems to present an interface to python (I can import the module 
and call the method) but I can't figure out how to get my data to the 
interface - I either get an error message about incorrect type 
(double**) or a segmentation fault.

I guess one of the main issues from the documentation is that I am 
unclear as to what goes where (e.g what goes in the *.i file, what goes 
in the C heard file, what goes in a python file).

Any guidance would be greatly appreciated.

Thanks,

Eric