Skip Menu |

This queue is for tickets about the Statistics-TTest CPAN distribution.

Report information
The Basics
Id: 37109
Status: new
Priority: 0/
Queue: Statistics-TTest

Owner: Nobody in particular
Requestors: b.e.buck [...]

Bug Information
Severity: (no value)
Broken in: (no value)
Fixed in: (no value)

CC: bug-Statistics-ttest [...]
Subject: Divide by zero in fdist module
Date: Wed, 25 Jun 2008 16:27:10 -0400
To: bug-Statistics-Distributions [...]
From: b.e.buck [...]
Download (untitled) / with headers
text/plain 739b
line 325/326 sub _subf2 has data vulnerabilities when called from t-test. It can wind up trying to take log's of negative numbers or dividing by zero if $n (the sample size) is sufficiently large that ($n - 2) * log($x) winds up being very negative, resulting in an exponent of a negative number. $x is frequently negative such that this can happen easily for large $n. Module 1.02 of Statistics::Distributions PERL 5.84 A trivial fix is to return $x = 1 for $z=>0 and $x = 0 for $x=>negative, but that may not be the desired behavior. You'd have to be much better at statistics and understanding what this part of the f-test calculation is actually *doing* to know if that's the right behavior. Thanks for any help on this, -- Ben

This service is sponsored and maintained by Best Practical Solutions and runs on infrastructure.

Please report any issues with to