[NumPy-Tickets] [NumPy] #1546: function prod fails over arrays without warm
NumPy Trac
numpy-tickets@scipy....
Thu Jul 15 06:24:18 CDT 2010
#1546: function prod fails over arrays without warm
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Reporter: mmarquez | Owner: somebody
Type: defect | Status: new
Priority: normal | Milestone: 2.0.0
Component: Other | Version:
Keywords: function prod |
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I'm a begginer using python. As a very simply exercise I was defining the
fact function, but I had a very bad surprise. The output of
{{{
import numpy
def fact(n):
return numpy.prod(range(2,n+1))
for i in range(2,50,5):
print "Fact of i %d is %d"%(i,fact(i))
}}}
is
{{{
Fact of i 2 is 2
Fact of i 7 is 5040
Fact of i 12 is 479001600
Fact of i 17 is -288522240
Fact of i 22 is -522715136
Fact of i 27 is 1484783616
Fact of i 32 is -2147483648
Fact of i 37 is 0
Fact of i 42 is 0
Fact of i 47 is 0
}}}
which is obviously''' wrong'''. But even more, this happen '''without any
warning or error messages'''.
This is wrong even if the computations are made using modular arithmetic
as claimed by the help.
--
Ticket URL: <http://projects.scipy.org/numpy/ticket/1546>
NumPy <http://projects.scipy.org/numpy>
My example project
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