如何修復編譯器錯誤：不能轉換爲Cython + numpy的指針類型？

Question

我想在Python中使用Cython和numpy來包裝C函數。

我編譯時出現以下錯誤：

_fastlp.c: In function ‘__pyx_pf_6fastlp_fastlp_func’: 
_fastlp.c:1351:3: error: cannot convert to a pointer type 
    fastlp(((double *)PyArray_DATA(((PyArrayObject *)__pyx_v_obj))), 
    ((double *)PyArray_DATA(((PyArrayObject *)__pyx_v_mat))), 
    ((double *)PyArray_DATA(((PyArrayObject *)__pyx_v_rhs))), (&__pyx_v_m0), 
    (&__pyx_v_n0), ((double *)PyArray_DATA(__pyx_v_opt)), 
    (&__pyx_v_status), ((double *)__pyx_v_lam)); 
    ^

箭頭^點(&__pyx_v_status)。

我.pyx文件是：

import numpy as np 
cimport numpy as np 

np.import_array() 

# cdefine the signature of the c function 
cdef extern from "fastlp.h": 
    void fastlp(double *obj, double *mat, double *rhs, int *m0 , int *n0, 
       double *opt, int *status, double *lam) 

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): 

    #Define output 
    cdef np.ndarray opt = np.zeros((len(obj),), dtype = np.float64) 
    cdef int status = 0 

    #Call external C function 
    cdef int m0 = mat.shape[0] 
    cdef int n0 = mat.shape[1] 

    fastlp(<double*> np.PyArray_DATA(obj), 
      <double*> np.PyArray_DATA(mat), 
      <double*> np.PyArray_DATA(rhs), 
      &m0, 
      &n0, 
      <double*> np.PyArray_DATA(opt), 
      &status, 
      <double*> lam) 

    return (opt,status) 

任何幫助，不勝感激！我一直在研究這麼久，我想我很接近。謝謝！

Answer 1

原來，我所需要的只是使用<double*> &lam來調用外部函數。我試圖把一個變量轉換成一個指針......當我不應該有。