Re: PSPP-BUG: Mac version of PSPP crashes with 2x2 crosstabulations

[Ben Pfaff]

On Fri, Dec 28, 2018 at 12:57:07PM -0500, Thomas Hargrove wrote:
> Dear PSPP Development Team:
> 
> System locks and PSPP must be forced to quit whenever a 2x2 cell 
> crosstabulation (contingency table) is requested with the selected (default) 
> option of Chi Square under statistics. This crash is somewhat logical since 
> standard standard Chi Square should not be run on a 2x2 table. Commercial 
> SPSS fixes this dilemma by running an adjusted Chi calculation.
> 
> This crash occurs with Mac PSPP version builds 1.1.0 and 1.2.0. Am running 
> current iOS Mojave 10.14.2, but this bug has occurred consistently over all 
> recent iOS versions. I reported this bug about a few years ago and believe it 
> was fixed in one of the earlier versions, but has returned in PSPP 1.1 and 
> 1.2.
> 
> Here is the formula for calculating an adjusted Chi values for contingency 
> tables:
> http://math.hws.edu/javamath/ryan/ChiSquare.html 
> <http://math.hws.edu/javamath/ryan/ChiSquare.html>

Thanks a lot for the report!  If you have a small example handy of
syntax that triggers the crash, then it would make it easy to identify
and fix and avoid further recurrence in the future (by adding it as one
of the PSPP test cases).  It would be even better if the example
included the adjusted Chi values that should appear in the output
because that would make it possible to verify that the additional
calculations were being done correctly.  If you can help with this, it
would be much appreciated.

I'm glad that PSPP is helpful!