Deprecating reload() ???

[David MacQuigg]

On Tue, 16 Mar 2004 19:48:06 -0600, Skip Montanaro <skip at pobox.com>
wrote:

>For timing stuff like this I recommend you use timeit.py.  Most people here
>are getting used to looking at its output.

Excellent utility.  This ought to be highlighted in the docs on the
time module, at least listed under "See also".  I just grabbed the
first thing that came up and wrote my own little routine around the
clock() function.

[...]
>Post code and results and we'll be happy to throw darts... :-)

# PZfuncs.py  --  Timing test for reloaded constants.

# Local constants:
h0 = 1
z1 = 1; z2 = 1
p1 = -1 +1j; p2 = -1 -1j; p3 = -1
pi = 3.1415926535897931

import Constants

def h23null(freq):
    pass

def h23a(freq):
    s = complex(2*pi*freq)
    return h0*(s-z1)*(s-z2)/((s-p1)*(s-p2)*(s-p3))

def h23b(freq):
    z = Constants
    s = complex(2*pi*freq)
    return z.h0*(s-z.z1)*(s-z.z2)/((s-z.p1)*(s-z.p2)*(s-z.p3))

def h23c(freq):
    h0 = Constants.h0
    z1 = Constants.z1; z2 = Constants.z2
    p1 = Constants.p1; p2 = Constants.p2; p3 = Constants.p3
    s = complex(2*pi*freq)
    return h0*(s-z1)*(s-z2)/((s-p1)*(s-p2)*(s-p3))

% timeit.py -s "from PZfuncs import * ; freq = 2.0" "h23null(freq)"
1000000 loops, best of 3: 0.461 usec per loop
% timeit.py -s "from PZfuncs import * ; freq = 2.0" "h23a(freq)"
100000 loops, best of 3: 4.94 usec per loop
% timeit.py -s "from PZfuncs import * ; freq = 2.0" "h23b(freq)"
100000 loops, best of 3: 5.79 usec per loop
% timeit.py -s "from PZfuncs import * ; freq = 2.0" "h23c(freq)"
100000 loops, best of 3: 6.29 usec per loop

My conclusion is that I should stick with form c in my application.
The savings from moving these assignments outside the function (form
a) does not justify the cost in possible problems after a reload.  The
savings in going to form b is negligible.  Form a is the easiest to
read, but forms b and c are not much worse.

These functions will typically be used in the interactive part of the
program to set up plots with a few hundred points.  The time-consuming
computations are all done in the simulator, which is written in C++.

-- Dave