in this link: http://earthpy.org/speed.html I found the following
%%cython
import numpy as np
def useless_cython(year):
# define types of variables
cdef int i, j, n
cdef double a_cum
from netCDF4 import Dataset
f = Dataset('air.sig995.'+year+'.nc')
a = f.variables['air'][:]
a_cum = 0.
for i in range(a.shape[0]):
for j in range(a.shape[1]):
for n in range(a.shape[2]):
#here we have to convert numpy value to simple float
a_cum = a_cum+float(a[i,j,n])
# since a_cum is not numpy variable anymore,
# we introduce new variable d in order to save
# data to the file easily
d = np.array(a_cum)
d.tofile(year+'.bin')
print(year)
return d
It seems to be as easy as to just write %%cython over the function. However this just doesnt work for me -> "Statement seems to have no effect" says my IDE. After a bit of research I found that the %% syntax comes from iphyton which I did also install (as well as cython). Still doesnt work. Iam using python3.6 Any ideas?
Once you are in the IPython interpreter you have to load the extension prior to using it. It can be done with the statement %load_ext, so in your case :
%load_ext cython
These two tools are pretty well documented, if you have not seen it yet, take a look at the relevant part of the document on cython side and on IPython side.