相关疑难解决方法(0)

我正在为numpy编写一个新的随机数生成器,当我遇到这个非常奇怪的行为时,根据任意分布生成随机数:

这是test.pyx

#cython: boundscheck=False
#cython: wraparound=False
import numpy as np
cimport numpy as np
cimport cython

def BareBones(np.ndarray[double, ndim=1] a,np.ndarray[double, ndim=1] u,r):
    return u

def UntypedWithLoop(a,u,r):
    cdef int i,j=0
    for i in range(u.shape[0]):
        j+=i
    return u,j

def BSReplacement(np.ndarray[double, ndim=1] a, np.ndarray[double, ndim=1] u):
    cdef np.ndarray[np.int_t, ndim=1] r=np.empty(u.shape[0],dtype=int)
    cdef int i,j=0
    for i in range(u.shape[0]):
        j=i
    return r

setup.py

from distutils.core import setup
from Cython.Build import cythonize
setup(name = "simple cython func",ext_modules = cythonize('test.pyx'),)

分析代码

#!/usr/bin/python
from __future__ import division

import …

功能

PyObject* PyArray_TypeObjectFromType(int);

将NumPy标量类型(NPY_BOOL,NPY_BYTE,...)的类型编号转换为相应的类型对​​象.

你如何进行相反的转换,从NumPy标量类型的类型对象到相应的类型号？

编辑:以下代码基于kwatford的答案.它接受类型对象(如int和numpy.int16)和字符串(如"int",u"int"和"int16").

int numpyScalarTypeNumber(PyObject* obj)
{
    PyArray_Descr* dtype;
    if(!PyArray_DescrConverter(obj, &dtype)) return NPY_NOTYPE;
    int typeNum = dtype->type_num;
    Py_DECREF(dtype);
    return typeNum;
}