[NumPy-Tickets] [NumPy] #1098: variance is inaccurate for arrays of identical, large values
NumPy Trac
numpy-tickets@scipy....
Wed Jan 26 10:14:06 CST 2011
#1098: variance is inaccurate for arrays of identical, large values
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Reporter: thouis | Owner: charris
Type: defect | Status: needs_review
Priority: normal | Milestone: Unscheduled
Component: numpy.core | Version: devel
Keywords: |
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Comment(by bsouthey):
At least on Linux, this can be addressed by the dtype argument:
{{{
import numpy as np
>>> (np.ones(100000)*10.0**20).var(dtype=np.float64)
52756253943791624.0
>>> (np.ones(100000)*10.0**20).var(dtype=np.float128)
0.0
}}}
Of course it just delays the situation when using even larger numbers.
--
Ticket URL: <http://projects.scipy.org/numpy/ticket/1098#comment:5>
NumPy <http://projects.scipy.org/numpy>
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