我在从R软件包（fastclime）编译C中的特定源文件时遇到问题，因此我可以将其用作Python模块。这是我在线提取R包的代码：
from __future__ import division
import os
import sys
import glob
if not os.path.exists('fastlp.h'):
! wget http://cran.r-project.org/src/contrib/fastclime_1.2.4.tar.gz
! tar -xzvf fastclime_1.2.4.tar.gz
在R包中（在[src]文件夹中）是源文件[parametric.c]。我想在Python中将其编译为具有numpy输入的模块。由于我无法立即测试此代码的功能，我首先尝试编译[fastlp.c]源文件。使用fastlp，我可以创建一个玩具示例来测试我是否在Python中成功编译了fastlp版本。然后我可以扩展编译[parametric.c]
的步骤这是我的尝试：
1）首先我创建头文件，因为它不存在
%%file fastclime/src/fastlp.h
int ratio_test0(double *dy, int *idy,int ndy, double *y, double *ybar, double mu);
void fastlp(double *obj, double *mat, double *rhs, int *m0 , int *n0, double *opt, int *status, double *lam)
void solver20(int m,int n,int nz,int *ia, int *ka, double *a,double *b, double *c)
int ratio_test0(double *dy, int *idy,int ndy,double *y, double *ybar, double mu)
2）接下来，我在Cython中编写用于包装C代码的文件：
%%file fastlp.pxd
cdef extern from "fastclime/src/fastlp.h":
void fastlp(double *obj, double *mat, double *rhs, int *m0 , int *n0, double *opt, int *status, double *lam)
%%file fastlp.pyx
cimport fastlp
def fastlp(double *obj, double *mat, double *rhs, int *m0 , int *n0, double *opt, int *status, double *lam):
fastlp.fastlp(*obj, *mat, *rhs, *m0, *n0, *opt, *status, *lam)
3）接下来我使用distutils构建系统进行编译。
%%file setup.py
from distutils.core import setup, Extension
from Cython.Build import cythonize
ext = Extension("fastlp",
sources=["fastlp.pyx", "fastclime/src/fastlp.c"])
setup(name="fastlp",
ext_modules = cythonize([ext]))
4）最后我编译
! python setup.py build_ext -i
＃4是事情失败的地方。不确定如何在步骤1-3中解决它。
5）如果一切都成功（它不是），我应该可以运行这段代码（取自小插图）
import fastlp as flp
import numpy as np
A=np.array([-1.0,-1,0,1,-2,1]).reshape((3,2))
b=np.array([-1.0,-2,1])
c=np.array([-2.0,3])
flp.fastlp(c,A,b)
这应该输出矢量[2.，1。]。
我对Cython或Python不太熟悉，但获得此功能对未来的项目有很大帮助。有人可以让我知道在C中获取源文件的正确方法，并完成与numpy接口创建Python模块的步骤吗？
谢谢！
更新：
我试图关注此网站上的Numpy + Cython示例：https://scipy-lectures.github.io/advanced/interfacing_with_c/interfacing_with_c.html
我已经更新了我的代码
%%cython
# import both numpy and the Cython declarations for numpy
import numpy as np
cimport numpy as np
# if you want to use the Numpy-C-API from Cython
# (not strictly necessary for this example)
np.import_array()
# cdefine the signature of our c function
cdef extern from "/home/bitnami/STA663-pura-project/fastclime/src/fastlp.h":
void fastlp(double *obj, double *mat, double *rhs, int *m0 , int *n0, double *opt, int *status, double *lam)
# create the wrapper code, with numpy type annotations
def fastlp_func(np.ndarray[double, ndim=1, mode="c"] obj not None,
np.ndarray[double, ndim=2, mode="c"] mat not None,
np.ndarray[double, ndim=1, mode="c"] rhs not None,
double lam):
cdef int m1 = mat.shape[0]
cdef int m2 = mat.shape[1]
cdef np.ndarray[double, ndim=1, mode='c'] z = np.zeros(obj.shape[0])
cdef double [:] zp = z #convert from Python to C object
cdef int stat = 0
cdef double lambd = 0
fastlp(<double*> np.PyArray_DATA(obj),
<double*> np.PyArray_DATA(mat.T),
<double*> np.PyArray_DATA(rhs),
&m1,
&m2,
&zp[0],
&stat,
&lambd
)
但是，我收到以下错误（我根本不理解）：
---------------------------------------------------------------------------
ImportError Traceback (most recent call last)
<ipython-input-85-29981393af41> in <module>()
----> 1 get_ipython().run_cell_magic(u'cython', u'', u'# import both numpy and the Cython declarations for numpy\nimport numpy as np\ncimport numpy as np\n\n# if you want to use the Numpy-C-API from Cython\n# (not strictly necessary for this example)\nnp.import_array()\n\n# cdefine the signature of our c function\ncdef extern from "/home/bitnami/STA663-pura-project/fastclime/src/fastlp.h":\n void fastlp(double *obj, double *mat, double *rhs, int *m0 , int *n0, double *opt, int *status, double *lam)\n \n# create the wrapper code, with numpy type annotations\ndef fastlp_func(np.ndarray[double, ndim=1, mode="c"] obj not None,\n np.ndarray[double, ndim=2, mode="c"] mat not None,\n np.ndarray[double, ndim=1, mode="c"] rhs not None,\n double lam):\n cdef int m1 = mat.shape[0]\n cdef int m2 = mat.shape[1]\n cdef np.ndarray[double, ndim=1, mode=\'c\'] z = np.zeros(obj.shape[0])\n cdef double [:] zp = z #convert from Python to C object\n cdef int stat = 0\n cdef double lambd = 0\n fastlp(<double*> np.PyArray_DATA(obj),\n <double*> np.PyArray_DATA(mat.T),\n <double*> np.PyArray_DATA(rhs),\n &m1,\n &m2,\n &zp[0], \n &stat, \n &lambd \n )')
/home/bitnami/anaconda/lib/python2.7/site-packages/IPython/core/interactiveshell.pyc in run_cell_magic(self, magic_name, line, cell)
2160 magic_arg_s = self.var_expand(line, stack_depth)
2161 with self.builtin_trap:
-> 2162 result = fn(magic_arg_s, cell)
2163 return result
2164
/home/bitnami/anaconda/lib/python2.7/site-packages/IPython/extensions/cythonmagic.pyc in cython(self, line, cell)
/home/bitnami/anaconda/lib/python2.7/site-packages/IPython/core/magic.pyc in <lambda>(f, *a, **k)
191 # but it's overkill for just that one bit of state.
192 def magic_deco(arg):
--> 193 call = lambda f, *a, **k: f(*a, **k)
194
195 if callable(arg):
/home/bitnami/anaconda/lib/python2.7/site-packages/IPython/extensions/cythonmagic.pyc in cython(self, line, cell)
269 self._code_cache[key] = module_name
270
--> 271 module = imp.load_dynamic(module_name, module_path)
272 self._import_all(module)
273
ImportError: /home/bitnami/.cache/ipython/cython/_cython_magic_16feaf686ed172960f59fa6333ae74b5.so: undefined symbol: fastlp