User guide

NumPy User Guide, Release 1.9.0
’’’
setup.py file for logit.c
Note that since this is a numpy extension
we use numpy.distutils instead of
distutils from the python standard library.
Calling
$python setup.py build_ext --inplace
will build the extension library in the current file.
Calling
$python setup.py build
will build a file that looks like ./build/lib
*
, where
lib
*
is a file that begins with lib. The library will
be in this file and end with a C library extension,
such as .so
Calling
$python setup.py install
will install the module in your site-packages file.
See the distutils section of
’Extending and Embedding the Python Interpreter’
at docs.python.org and the documentation
on numpy.distutils for more information.
’’’
def configuration(parent_package=’’, top_path=None):
import numpy
from numpy.distutils.misc_util import Configuration
config = Configuration(’npufunc_directory’,
parent_package,
top_path)
config.add_extension(’npufunc’, [’single_type_logit.c’])
return config
if __name__ == "__main__":
from numpy.distutils.core import setup
setup(configuration=configuration)
After the above has been installed, it can be imported and used as follows.
>>> import numpy as np
>>> import npufunc
>>> npufunc.logit(0.5)
0.0
>>> a = np.linspace(0,1,5)
>>> npufunc.logit(a)
array([ -inf, -1.09861229, 0. , 1.09861229, inf])
5.3.4 Example Numpy ufunc with multiple dtypes
We finally give an example of a full ufunc, with inner loops for half-floats, floats, doubles, and long doubles. As in the
previous sections we first give the .c file and then the corresponding setup.py file.
86 Chapter 5. Using Numpy C-API