I am trying to use Cython to speed up some calculation with complex numpy arrays and I am getting this error: C:>python setup_post.py build_ext --inplace running build_ext cythoning SVDc_post.pyx to SVDc_post.c Error converting Pyrex file to C: ------------------------------------------------------------ ... # static inline Real csq(cComplex x) { return creal(x*conj(x)); } cdef inline double csq(x): return real(x*x.conjugate()) def SVDc2(int m, int n, ^ ------------------------------------------------------------ C:\SVDc_post.pyx:11:0: Compiler crash in IntroduceBufferAuxiliaryVars ModuleNode.body = StatListNode(SVDc_post.pyx:2:0) StatListNode.stats[4] = StatListNode(SVDc_post.pyx:11:0) StatListNode.stats[0] = DefNode(SVDc_post.pyx:11:0, modifiers = [...]/0, name = u'SVDc2', num_required_args = 7, reqd_kw_flags_cname = '0') The code is below (I removed all the code not relevant to this error): import numpy as np cimport numpy as np ctypedef np.float64_t dtype_t cdef inline double csq(x): return real(x*x.conjugate()) def SVDc2(int m, int n, np.ndarray[np.complex128_t, ndim = 2] Ao, np.ndarray[np.float64_t, ndim = 1] d, np.ndarray[np.complex128_t, ndim = 2] Vo, np.ndarray[np.complex128_t, ndim = 2] Wo, int sort): cdef dtype_t EPS = 1.5e-31 cdef dtype_t DBL_EPS = 2.2204460492503131e-16 cdef int maxsweeps = 50 cdef int err = True cdef int rev = ((m - n) >> 15) & 1 cdef int nm = min(m, n) cdef int nx = max(m, n) cdef dtype_t red = .01 / (nx * nx * nx * nx) cdef int ldV = nx cdef int ldW = nx cdef int ldA = nx cdef dtype_t thresh = 0.0 cdef np.ndarray[np.complex128_t, ndim=3] VW = zeros((3, nx, nx), dtype=complex128_t) cdef np.ndarray[np.int32, ndim=1] ppi = empty(nm, dtype=int32) for p in range(0, nx): VW[0, p, p] = 1 for p in range(0, nx): VW[1, p, p] = 1 if rev: for q in range(0, m): for p in range(0, n): VW[2, p, q] = Ao[q, p] else: for q in range(0,m): for p in range(0,n): VW[2, q, p] = Ao[q, p] return I was wondering if I need a special setup.py when using numpy arrays. Any ideas? Thanks, -Arrigo