On 1/27/07, Charles R Harris <[EMAIL PROTECTED]> wrote:
Hmmm, and your problem machine is running smp linux. As is mine; fedora uses
smp even on single processor machines these days. I think we could use more
data here comparing
OSX
Linux (single, smp)
Window
OK, this is weird. I modified the repeat code a little to ease
collecting of results, and all of a sudden the differences went away.
If you look at the attached code, here's what happens for me:
a) If I have line 77 like this (commented out):
#print '-'*75
I get:
[...]
94 z different 8.47032947254e-22
95 z different 8.47032947254e-22
96 z different 8.47032947254e-22
98 z different 8.47032947254e-22
99 z different 8.47032947254e-22
Numpy version: 1.0.2.dev3521
test1: 0 differences
test2: 75 differences
test3: 0 differences
b) If I remove the comment char from that line, I get:
tlon[~/Desktop]> python repeat.py
---------------------------------------------------------------------------
Numpy version: 1.0.2.dev3521
test1: 0 differences
test2: 0 differences
test3: 0 differences
That's it. One comment char removed, and something that's done
/after/ the tests are actually executed.
That kind of 'I add a printf() call and the bug disappears' is
unpleasantly reminiscent of lurking pointer errors in C code...
Cheers,
f
import numpy as N
import numpy.matlib as M
def load():
# x data
x = M.zeros((3,3))
x[0,0] = 0.00301404794991108
x[0,1] = 0.00264742266711118
x[0,2] = -0.00112705028731085
x[1,0] = 0.0228605377994491
x[1,1] = 0.00337153112741583
x[1,2] = -0.00823674912992519
x[2,0] = 0.00447839875836716
x[2,1] = 0.00274880280576514
x[2,2] = -0.00161133933606597
# y data
y = M.zeros((3,1))
y[0,0] = 0.000885398
y[1,0] = 0.00667193
y[2,0] = 0.000324727
return x, y
def calc(x, y):
return x * (x.T * y)
def test1(nsim=100):
x, y = load()
z0 = calc(x, y)
ndiff = 0
for i in xrange(nsim):
z = calc(x, y)
if (z != z0).any():
ndiff += 1
print i, 'z different', abs(z - z0).max()
return ndiff
def test2(nsim=100):
x0, y0 = load()
z0 = calc(x0, y0)
ndiff = 0
for i in xrange(nsim):
x, y = load()
z = calc(x, y)
if (x != x0).any():
print i, 'x different', abs(x - x0).max()
if (y != y0).any():
print i, 'y different', abs(y - y0).max()
if (z != z0).any():
print i, 'z different', abs(z - z0).max()
ndiff += 1
return ndiff
def test3(nsim=100):
x0, y0 = load()
z0 = calc(100*x0, y0) / (100 * 100)
ndiff = 0
for i in xrange(nsim):
x, y = load()
z = calc(100*x, y) / (100 * 100)
if (x != x0).any():
print i, 'x different', abs(x - x0).max()
if (y != y0).any():
print i, 'y different', abs(y - y0).max()
if (z != z0).any():
print i, 'z different', abs(z - z0).max()
ndiff += 1
return ndiff
def all():
n1 = test1()
n2 = test2()
n3 = test3()
print
print '-'*75
print 'Numpy version:',N.__version__
print
print 'test1: ', n1, ' differences'
print 'test2: ', n2, ' differences'
print 'test3: ', n3, ' differences'
all()
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