2016-04-13-cython.sagews

Cython

A Very Brief Introduction!

Cython website: http://cython.org/

And a mailing list thread from today: https://groups.google.com/forum/#!topic/cython-users/7zlP_j5Rd7w

# recall
def sin_sum(m):
    return sum(math.sin(i) for i in xrange(m))

%timeit sin_sum(10000)

125 loops, best of 3: 2.12 ms per loop

%cython
import math
def sin_sum_cython0(m):
    return sum(math.sin(i) for i in xrange(m))

Defined math, sin_sum_cython0

Auto-generated code...

%timeit sin_sum_cython0(10000)

125 loops, best of 3: 1.5 ms per loop

# not that impressive... but *typical*
2.12/1.5

1.41333333333333

Talk about type declaration and direct calling of C code...

%cython

cdef extern from "math.h":
    cdef double sin(double)

def sin_sum_cython(int m):
    cdef double s = 0
    cdef int k
    for k in range(m):
        s += sin(k)
    return s

Defined sin_sum_cython

Auto-generated code...

%timeit sin_sum_cython(10000)

625 loops, best of 3: 472 µs per loop

2.12/.472

4.49152542372881

def sin_sum0(m):
    return float(sum(sin(i) for i in xrange(m)))

%time sin_sum0(10000)

1.9395054106807317 CPU time: 3.88 s, Wall time: 3.94 s

# speedup over original: 10000x
3.94/.000397

9924.43324937028

You probably can't beat this by much without a new idea...