Integer From A Float List?!?

[andrea_gavana]

Hello NG,

sorry to bother you again with this question... I never used the "timeit"
function, and I would like to ask you if the call I am doing is correct:

C:\Python23\Lib>python timeit.py -n 1000 -s "from Numeric import ones" -s
"floa
ts=ones((1000,1),'f')" -s "ints = floats.astype(int)"
1000 loops, best of 3: 0.0536 usec per loop

I used Numeric module to create a 1000 floats matrix of ones, and it seems
to me that is a lot faster than other solutions... but probably I am doing
something wrong in my call to the timeit function...

Thank you a lot.

Andrea.

 

[Kent Johnson]

Hello NG,

sorry to bother you again with this question... I never used the "timeit"
function, and I would like to ask you if the call I am doing is correct:

C:\Python23\Lib>python timeit.py -n 1000 -s "from Numeric import ones" -s
"floa
ts=ones((1000,1),'f')" -s "ints = floats.astype(int)"
1000 loops, best of 3: 0.0536 usec per loop

The -s option indicates Setup steps that are done outside the timing loop. So you have timed 1000
empty loops, which is indeed impressively fast

The correct command is
C:\Python23\Lib>python23 timeit.py -n 1000 -s "from Numeric import ones" -s
"floats=ones((1000,1),'f')" "ints = floats.astype(int)"
1000 loops, best of 3: 30.7 usec per loop

which is still impressively fast compared to map:

C:\Python23\Lib>python timeit.py -s "floats = map(float, range(1000))" "ints= map(int, floats)"
1000 loops, best of 3: 572 usec per loop

Kent