[Visualpython-users] Efficiency

[James R. <u32...@an...>]

Hi,

I'm using vpython in computational simulation.  A little concerned about 
the efficiency, I ran the following tests:

from visual import *
import profile
import datetime

def dostuff(n):
    for i in range(n):
        for i in range(n):
            pass

timea = datetime.datetime.today()
profile.run("dostuff(1500)")
timeb = datetime.datetime.today()
t = timeb - timea
print "Actual running time: %i.%i seconds" % (t.seconds, t.microseconds)

ball = sphere(pos=(0,0,0), radius=1)

timea = datetime.datetime.today()
profile.run("dostuff(1500)")
timeb = datetime.datetime.today()
t = timeb - timea
print "Actual running time: %i.%i seconds" % (t.seconds, t.microseconds)


And I got this output:
Visual-2003-10-05
         3 function calls in 1.250 CPU seconds
   Ordered by: standard name
   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.000    0.000    1.240    1.240 <string>:1(?)
        1    0.010    0.010    1.250    1.250 profile:0(dostuff(1500))
        0    0.000             0.000          profile:0(profiler)
        1    1.240    1.240    1.240    1.240 visualanalysis.py:5(dostuff)
Actual running time: 1.338290 seconds
Xlib:  extension "XFree86-DRI" missing on display ":0.0".
         3 function calls in 2.040 CPU seconds
   Ordered by: standard name
   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.000    0.000    2.040    2.040 <string>:1(?)
        1    0.000    0.000    2.040    2.040 profile:0(dostuff(1500))
        0    0.000             0.000          profile:0(profiler)
        1    2.040    2.040    2.040    2.040 visualanalysis.py:5(dostuff)
Actual running time: 10.847798 seconds

This in my view is pretty poor efficiency, considering that visual 
python is doing nothing but displaying a static ball on the second call 
to dostuff().  Is there anyway to tell visual python to lay off and do 
nothing for a while?  So... in the context of my work, when I call the 
functions that do all the hard work, i would tell visual python to do 
nothing, and then when the functions return, i'd tell visual python to 
start doing stuff again.  BTW, what is it doing that slows everything 
down so much?

-- 
James Roper
Summer Research Scholar             Department of Computer Science
Fourth Year Software Engineer       Department of Computer Science
Australian National University

"A deceptively simple architectural challenge faced by many 
multi-tasking applications is gracefully doing nothing."
Glyph Lefkowitz