[Scipy-tickets] [SciPy] #745: scipy.stats.distribution - tests and bugfixes
SciPy
scipy-tickets@scipy....
Fri Oct 31 23:29:55 CDT 2008
#745: scipy.stats.distribution - tests and bugfixes
-------------------------+--------------------------------------------------
Reporter: josefpktd | Owner: somebody
Type: defect | Status: new
Priority: normal | Milestone:
Component: scipy.stats | Version: devel
Severity: normal | Resolution:
Keywords: |
-------------------------+--------------------------------------------------
Comment (by josefpktd):
An update: I incorporated improvements to my corrections proposed by Per
Brodtkorb
see http://projects.scipy.org/pipermail/scipy-
dev/2008-October/009829.html.
this I didn't find time to do:
{{{
In order to improve accuracy in calculation for small x values, I would
also suggest to replace all calls to
log(1-x) and 1-exp(-x)
with
log1p(-x) and -expm1(-x), respectively
}}}
I also wrote a basic test file for the continuous distributions, and found
several (?) additional bugs that I corrected in my distributions.py file.
Given the number of small bugs, I didn't write a separate bug report for
each. They are commented in the file and marked with #JP.
I haven't merged the latest changes of the scipy trunk to my file, which
is mainly the conversion of the Von Mises distribution to cython.
I attach my updated distributions.py and the testfile
test_continuous_basic.py. This file tests *all* continuous distributions
and has DECIMAL as a parameter for the assert_almost_equal comparison.
With Decimal=2, I now get for the cdf,ppf,pdf,rvs,sf,isf tests:
{{{
Ran 410 tests in 124.187s
FAILED (errors=2, failures=10)
}}}
Of the failures, several are with vonmises, and some might be caused by a
numerically imprecise test. The tests are based on "nice" parameters, from
my fuzz testing, I know that additional tests fail where the distributions
don't work over the entire valid parameter space.
But my bugfixes, make the generic methods work correctly (as far as I got)
and many of the FIXMEs can be removed.
Josef
--
Ticket URL: <http://scipy.org/scipy/scipy/ticket/745#comment:5>
SciPy <http://www.scipy.org/>
SciPy is open-source software for mathematics, science, and engineering.
More information about the Scipy-tickets
mailing list