我使用SWIG在Python中创建了一个* .so文件,但是当我导入它时,我得到了这个:
/_analyzer.so: undefined symbol: autocorellation
我根据这条指示几乎完成了所有事情:https://scipy.github.io/old-wiki/pages/Cookbook/SWIG_NumPy_examples.html
我的代码如下:
analyzer.h:
void autocorellation(double *in, double *out, long long n);
analyzer.cpp:
#include "analyzer.h"
#include <math.h>
#include <stdlib.h>
#define PI 3.14159265358979323846
typedef struct {
double real;
double im;
} Complex;
void complex_multiply(Complex a,Complex b,Complex* c){
c->real = a.real * b.real - a.im * b.im;
c->im = a.real * b.im + a.im * b.real;
}
void complex_multiply_int(int a, Complex b,Complex* c){
c->real = a * b.real;
c->im = a * b.im;
}
void complex_sum(Complex a,Complex b,Complex* c){
c->real = a.real + b.real;
c->im = a.im + b.im;
}
void complex_conjugate(Complex* a,Complex* b,long long n){
for(int i = 0; i < n; ++i){
b[i].real = a[i].real;
b[i].im = -1 * a[i].im;
}
}
long long rev (long long num, long long lg_n) {
long long res = 0;
for (long long i=0; i < lg_n; ++i)
if (num & (1 << i))
res |= 1 << (lg_n-1-i);
return res;
}
void fft (Complex* a, long long n,bool invert) {
long long lg_n = 0;
while ((1 << lg_n) < n)
++lg_n;
for (long long i=0; i<n; ++i){
long long r= rev(i,lg_n);
if (i < r){
a[i].real = a[i].real + a[r].real;
a[r].real = a[i].real - a[r].real;
a[i].real = a[i].real - a[r].real;
a[i].im = a[i].im + a[r].im;
a[r].im = a[i].im - a[r].im;
a[i].im = a[i].im - a[r].im;
}
}
for (long long len=2; len<=n; len <<= 1) {
double ang = 2*PI/len * (invert ? -1 : 1);
Complex wn;
wn.real = cos(ang);
wn.im = sin(ang);
for (long long i=0; i<n; i+=len) {
Complex w;
w.real = 1;
w.im = 0;
long long ll = (long long)(len * 0.5);
for (long long j=0; j< ll; ++j) {
Complex u = a[i+j],v;
complex_multiply(a[i+j+ll],w,&v);
complex_sum(u,v,&a[i+j]);
complex_multiply_int(-1,v,&v);
complex_sum(u,v,&a[i+j+ll]);
complex_multiply(w,wn,&w);
}
}
}
if (invert)
for (long long i=0; i<n; ++i){
a[i].real /= n;
a[i].im /= n;
}
}
void autocorellation(double *in, double *out, long long n){
long long le = 1;
while(n > le)
le *= 2;
double m = 0;
for(int i = 0; i < n; ++i)
m+=in[i];
m /= n;
for(int i = 0; i < n; ++i)
in[i] -= m;
Complex* a = (Complex*) malloc(le*sizeof(Complex));
Complex* b = (Complex*) malloc(le*sizeof(Complex));
for(long long i = 0; i < n; ++i){
a[i].im = 0;
a[i].real = in[i];
}
for(long long i = n; i < le; ++i){
a[i].im = 0;
a[i].real = 0;
}
fft(a,le,false);
complex_conjugate(a,b,le);
Complex* c = (Complex*) malloc(le*sizeof(Complex));
for(long long i = 0; i < le; ++i)
complex_multiply(b[i],a[i],&c[i]);
fft(c,le,true);
for(long long i = 0; i < n; ++i)
out[i] = (c[i].real/c[0].real);
free(a);
free(b);
free(c);
}
analyzer.i:
%module analyzer
%{
#define SWIG_FILE_WITH_INIT
#include "analyzer.h"
%}
%include "numpy.i"
%init %{
import_array();
%}
%apply (double* IN_ARRAY1,int DIM1) {(double *in, long long n)}
%apply (double* ARGOUT_ARRAY1,int DIM1) {(double *out, long long n)}
%include "analyzer.h"
setup.py:
#! /usr/bin/env python
# System imports
from distutils.core import *
from distutils import sysconfig
# Third-party modules - we depend on numpy for everything
import numpy
# Obtain the numpy include directory. This logic works across numpy versions.
try:
numpy_include = numpy.get_include()
except AttributeError:
numpy_include = numpy.get_numpy_include()
# ezrange extension module
_analyzer = Extension("_analyzer",
["analyzer.i","analyzer.cpp"],
include_dirs = [numpy_include],
)
# ezrange setup
setup( name = "range function",
description = "Autocorellation function evaluation",
author = "Bodya",
version = "1.0",
ext_modules = [_analyzer]
)
答案 0 :(得分:0)
您的代码和cookbook示例之间的区别在于您的代码是C ++。因此,您需要将-c++
选项传递给SWIG。在setup.py中构建Extension(...)
时,只需添加swig_opts=['-c++'],
。
请注意,distutils仍将在生成的包装器文件上调用C编译器,但这将具有.cpp
扩展名,因此如果编译器是gcc或clang,则应该正确编译它。
我使用distutils或setuptools进行C ++ SWIG扩展的经验一直很差,所以我调用SWIG在distutils之外生成一个包装器(我是通过Makefile完成的)并且只使用distutils来编译扩展来自包装文件。