[vtk-developers] Failing Test: TestDescriptiveStatistics needs attention

[Bill Lorensen]

Folks,

The subject test is failing on many platforms:
http://www.cdash.org/CDash/testSummary.php?project=11&name=Infovis-TestDescriptiveStatistics&date=2009-12-28

According to cdash, the test has been failing since Dec 22 when these
files were checked in:
http://www.cdash.org/CDash/viewUpdate.php?buildid=499182

This continuous build was the first to notice the problem:
http://www.cdash.org/CDash/viewTest.php?onlyfailed&buildid=498908

I ran the test in the debugger and here is the failing statement:
Program received signal SIGFPE, Arithmetic exception.
0x0095f351 in vtkDescriptiveStatistics::Test (this=0x8764fe8,
    inData=0x87642a0, inMetaDO=0x8766f40, outMetaDO=0x87672b0)
    at /home/lorensen/Projects/VTKHead/Infovis/vtkDescriptiveStatistics.cxx:536
536	    double s = sqrt( n / ( m22 * m2 ) ) * m3;

This is a result of
Warning: In /projects/kmorel/dashboard/VTK/Infovis/vtkDescriptiveStatistics.cxx,
line 282
vtkDescriptiveStatistics (0x59a0c0): InData table does not have a
column Metric 3. Ignoring it.

Warning: In /projects/kmorel/dashboard/VTK/Infovis/vtkUnivariateStatisticsAlgorithm.cxx,
line 122
vtkDescriptiveStatistics (0x59a0c0): InData table does not have a
column Metric 3. Ignoring it.


The test purposely adds a bogus column. This causes the zero divide.
Since VTK does not throw exceptions, the bad data needs to be handled
in an alternative way to avoid the 0 divide.

It is easy to miss a defect like this because the vtk dashboard seems
to have many tests failing on a continuing basis.

Bill