如何将复数从python numpy传递给c(目前尝试使用SWIG)

我想用python调用带有复数输入的c编写函数.我尝试使用SWIG生成包装器-但它似乎掉下来了.我认为我需要找出适合在numpy.i中使用的“宏”-但不确定是什么-任何人对此都有任何经验-或其他可以解决此问题的方法？

numpy.i在底部显示了它-尽管已被注释掉.我尝试使用这些宏-但是它们失败了,SWIG抱怨我尝试了以下宏扩展的语法错误：

%numpy_typemaps(complex float, NPY_CFLOAT , int)
%numpy_typemaps(complex double, NPY_CDOUBLE, int)
%numpy_typemaps(complex long double, NPY_CLONGDOUBLE, int)

这些是我的文件：

ComplexNumbers.c

# include <math.h>
# include <complex.h>


double complex returnX(double complex X) 
/*
    fresnel reflection coefficient rs
*/
{
    return X;
}

ComplexNumbers.i：

%{
#define SWIG_FILE_WITH_INIT
%}
%include "numpy.i"
%init %{
import_array();
%}


%module ComplexNumbers

%inline %{
extern double complex returnX(double complex X);
%}

Python：

#!/usr/bin/env python

"""
setup.py file for ComplexNumbers
"""

from distutils.core import setup
from distutils.extension import Extension

import numpy


ComplexNumbers_module = Extension('_ComplexNumbers',
                           sources=['ComplexNumbers_wrap.c', 
                                    'ComplexNumbers.c'],
                           include_dirs=[numpy.get_include()]
                           )

setup (name = 'ComplexNumbers',
       version = '1.0',
       author      = "JP Hadden jp.hadden@bristol.ac.uk",
       description = """Spectral Interfereometry functions""",
       ext_modules = [ComplexNumbers_module],
       py_modules = ["ComplexNumbers"],
       )

编译器输出错误

C:\MinGW32-xy\bin\gcc.exe -mno-cygwin -mdll -O -Wall -IC:\Python27\lib\site-pack
ages\numpy\core\include -IC:\Python27\include -IC:\Python27\PC -c ComplexNumbers
_wrap.c -o build\temp.win32-2.7\Release\complexnumbers_wrap.o
ComplexNumbers_wrap.c:2975:23: error: expected '=', ',', ';', 'asm' or '__attrib
ute__' before 'returnX'
ComplexNumbers_wrap.c: In function '_wrap_returnX':
ComplexNumbers_wrap.c:2982:18: error: expected '=', ',', ';', 'asm' or '__attrib
ute__' before 'arg1'
ComplexNumbers_wrap.c:2982:18: error: 'arg1' undeclared (first use in this funct
ion)
ComplexNumbers_wrap.c:2982:18: note: each undeclared identifier is reported only
 once for each function it appears in
ComplexNumbers_wrap.c:2986:18: error: expected '=', ',', ';', 'asm' or '__attrib
ute__' before 'result'
ComplexNumbers_wrap.c:2986:18: error: 'result' undeclared (first use in this fun
ction)
ComplexNumbers_wrap.c:2997:24: error: expected ')' before 'complex'
ComplexNumbers_wrap.c:2997:24: error: pointer value used where a floating point
value was expected
ComplexNumbers_wrap.c:2997:14: error: invalid type argument of unary '*' (have '
double')
ComplexNumbers_wrap.c:3000:20: error: expected ')' before 'complex'
ComplexNumbers_wrap.c:3000:20: warning: implicit declaration of function 'return
X'
ComplexNumbers_wrap.c:3001:15: error: expected ')' before 'complex'
ComplexNumbers_wrap.c:3001:15: error: expected ')' before 'complex'
ComplexNumbers_wrap.c:3001:15: error: expected ')' before 'complex'
ComplexNumbers_wrap.c:3001:15: error: pointer value used where a floating point
value was expected
ComplexNumbers_wrap.c:3001:15: error: expected ')' before 'complex'
ComplexNumbers_wrap.c:3001:15: error: incompatible type for argument 1 of 'memcp
y'
c:\mingw32-xy\bin\../lib/gcc/mingw32/4.5.2/../../../../include/string.h:38:40: n
ote: expected 'void *' but argument is of type 'double'
error: command 'gcc' failed with exit status 1

解决方法:

我不确定它如何与Numpy交互,但是SWIG当然包括对C99复杂类型的支持.我可以使用以下示例对此进行验证：

%module test
%{
#include <complex.h>
%}

%include <complex.i>

%inline %{
  double complex test(double complex X) {
    return X;
  }
%}

这使用了SWIG complex.i接口.

(请注意,这里％inline用于声明,定义和包装所有内容-方便进行测试,但是对于“真实”代码,我倾向于使用％include).

我在Linux上使用以下命令对此进行了编译：

swig -Wall -python test.i 
gcc -std=c99 -Wall -Wextra test_wrap.c -I/usr/include/python2.7 -shared -o _test.so

内置一个警告就很好.完成后,我可以执行以下操作：

LD_LIBRARY_PATH=.  python                       
Python 2.7.3 (default, Aug  1 2012, 05:16:07) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import test
>>> test.test(complex(0,1))
1j
>>> test.test(complex(0,2))
2j
>>> test.test(complex(1,2))
(1+2j)
>>> 

似乎正在接受并返回本机Python复杂类型.

我还能够编译以下接口：

%{
#define SWIG_FILE_WITH_INIT
#include <complex.h>
%}
%include <complex.i>
%include <numpy.i>
%init %{
import_array();
%}

%numpy_typemaps(complex float, NPY_CFLOAT , int)
%numpy_typemaps(complex double, NPY_CDOUBLE, int)
%numpy_typemaps(complex long double, NPY_CLONGDOUBLE, int)

%module test

%inline %{
  double complex test(double complex X) {
    return X;
  }
%}

通过添加％include< complex.i&gt ;,和-std = c99到编译器标志.我认为您可以使用these options之类的东西为distutils设置它.

标签：swig,c-3,python,numpy
来源： https://codeday.me/bug/20191127/2077047.html