Numpy.i typemap for multiple arrays of different types

Question

I have a C function which takes, among other arguments, 3 arrays of differents types : void create_signal(double ztab[], ..., int *pdata, ..., char ranging[], ...); and I want to use this function in a Python module using SWIG.

I have already figured out how to use C functions which take in an array with numpy.i typemaps : %apply (double* INPLACE_ARRAY1, int DIM1) {(double xtab[], int length)} for instance,

or even 2 arrays of same type : apply (double* INPLACE_ARRAY1, int DIM1) {(double xtab[], int length_x), (double ytab[], int length_y)}

but I can't figure out if it is possible to do so if the arrays are of different types (in my case, int, double, and char), or if I should rewrite my own typemap.

Thanks for your help !

Answer 1

Anyway, here goes an example

test.h

#pragma once

void multipleInputs(const float* data, const int nData,
                    const float* pos, const int nPositions, const int nDim);

test.cpp

#include "test.h"

#include <cstdio>

void multipleInputs(const float* data, const int nData,
                    const float* pos, const int nPositions, const int nDim)
{
  if (nData > 0) {
    printf("%d'th element is: %f\n", (nData-1), data[nData-1]);
  }
  if ((nDim > 0) && (nPositions > 0)){
    printf("%d'th dimension of the %d'th element is: %f\n",
           (nDim-1), (nPositions-1), data[nData-1]);
  }
}

test.i

%module example
%{
  #define SWIG_FILE_WITH_INIT
  #include "test.h"
%}

%include "numpy.i"

%init {
  import_array();
}

%apply (float* IN_ARRAY1, int DIM1) \
{(const float* data, const int nData)}

%apply (float* IN_ARRAY2, int DIM1, int DIM2) \
{(const float* pos, const int nPositions, const int nDim)};

%include "test.h"

setup.py

import numpy

from setuptools import setup, Extension

setup(name="example",
      py_modules=["example"],
      ext_modules=[Extension("_example",
                             ["test.i","test.cpp"],
                             include_dirs = [numpy.get_include(), '.'],
                             swig_opts=['-c++', '-I.'],
      )]
)

test.py

import example
example.multipleInputs(np.ones((10),dtype=np.float32), 
                       np.ones((10,10),dtype=np.float32))