No speed gains from Cython

Question

I am trying to define a function that contains an inner loop for simulating an integral.

The problem is speed. Evaluating the function once can take up to 30 seconds on

Answer 1

Splitting data only, after your comment on 28 Nov:

import sys
import time
import numpy as np

def splitdata( data, n, start=1971 ):
    """ split data into n pieces, where col 1 == start .. start + n """
        # not fancy, fast enough for small n
    split = n * [None]
    for j in range(n):
        split[j] = data[ data[:,1] == start + j ]
    return split  # [ arrays: col1 0, col1 1 ... ]

#...........................................................................
N = 2237
ncol = 21
start = 1971
n = 20
seed = 1
exec "\n".join( sys.argv[1:] )  # run this.py N= ...
np.set_printoptions( 2, threshold=100, suppress=True )  # .2f
np.random.seed(seed)

print "N=%d  ncol=%d  n=%d" % (N, ncol, n)
data = np.random.uniform( start, start + n, (N,ncol) )
data[:,1] = data[:,1].round()
t0 = time.time()

split = splitdata( data, n, start )  # n pieces

print "time: %.0f us splitdata" % ((time.time() - t0) * 1e6)
for y, yeardata in enumerate(split):
    print "%d  %d  %g" % (start + y, len(yeardata), yeardata[:,0].sum())

-->

time: 27632 us splitdata  # old mac ppc
1971  69  136638
1972  138  273292
...