Changes between Initial Version and Version 1 of psVectorStats_ErrorHandling

Timestamp:

Apr 28, 2009, 10:47:33 AM (17 years ago)

Author:

eugene

Comment:

--

psVectorStats_ErrorHandling

@@ +1 @@
+Return to [wiki:Software_Development Software Development Page]
+
+psVectorStats traditionally raised a psError for cases where the input data simply resulted in an invalid statistic.  For example, if all input data points were masked or if the vector length was 0 (or in some cases 1).  Since IPP programs bail out if any errors were not handled, this ended up in lots of places where psErrorClear was used gratuitously to hide problems.
+
+I've changed the handling of psVectorStats to raise an error only in cases of serious programming or resource problems: unexpected NULL vectors, unallowed vector types, and so forth.  In cases where valid vectors are supplied (even if zero length),  a result of NAN is perfectly acceptable, and now does not raise an error.  
+
+I've also gone through all of the instances where psVectorStats is called and have added code to handle 'false' return status, and where possible to handle a NAN result as well.  Not all of these were immediately obvious, so at the bottom of this page I have a list of the files for which more work to handle the NANs could be added.
+
+There are a couple of unclear choices in the programming remaining: currently, any stats function which successfully calculates a non-NAN result raises its bit(s) in the psStats->result field.  These could be raised even if a NAN is calculated.  Also, it might be useful to have a bit somewhere that implies that the stats calculation failed: ie, it did not produce finite results for all of the desired output fields.
+
+{{{
+psModules/src/objects/pmGrowthCurveGenerate.c -- XXX does a poor job of handling NANs
+psModules/src/objects/pmPSFtry.c -- XXX does a poor job of handling NANs
+ppMerge/src/ppMergeMask.c -- XXX results are not handled well
+ppStats/src/ppStatsReadout.c -- XXX results are not handled well
+psLib/src/imageops/psImageBackground.c -- XXX results are not handled well
+psLib/src/imageops/psImageGeomManip.c -- XXX results are not handled well
+psLib/src/imageops/psImageMap.c -- XXX results are not handled well
+psLib/src/imageops/psImageMapFit.c -- XXX results are not handled well
+psLib/src/imageops/psImagePixelExtract.c -- XXX results are not handled well
+psLib/src/imageops/psImageStats.c -- XXX results are not handled well
+psLib/src/math/psClip.c -- XXX results are not handled well
+psLib/src/math/psMinimizePolyFit.c -- XXX results are not handled well
+psLib/src/math/psPolynomialUtils.c -- XXX results are not handled well
+psModules/src/astrom/pmAstrometryDistortion.c -- XXX results are not handled well
+psModules/src/camera/pmFPAMaskWeight.c -- XXX results are not handled well
+psModules/src/detrend/pmFringeStats.c -- XXX results are not handled well
+psModules/src/detrend/pmOverscan.c -- XXX results are not handled well
+}}}
+
+{{{
+ppImage/src/ppImageMeasureCrosstalk.c -- NAN results are data
+ppStats/src/ppStatsFromMetadataStats.c -- NAN results are data
+psastro/src/psastroAstromGuess.c -- NAN results are data
+psastro/src/psastroFixChipsTest.c -- NAN results are data
+psastro/src/psastroModelAnalysis.c -- NAN results are data
+psastro/src/psastroModelFitBoresite.c -- NAN results are data
+psastro/src/psastroZeroPoint.c -- NAN results are data
+psModules/src/concepts/pmConceptsStandard.c -- NAN results are data
+psModules/src/objects/pmSource.c -- NAN results are data
+psphot/src/psphotApResid.c -- NAN results are data
+psphot/src/psphotChoosePSF.c -- NAN results are data
+psphot/src/psphotDiagnosticPlots.c -- NAN results are data
+psphot/src/psphotImageQuality.c -- NAN results are data
+}}}
+
+{{{
+psModules/src/detrend/pmRemnance.c -- results are checked
+psModules/src/detrend/pmShutterCorrection.c -- results are checked
+psModules/src/extras/pmVisual.c -- results are checked
+psModules/src/imcombine/pmImageCombine.c -- results are checked
+psModules/src/imcombine/pmReadoutCombine.c -- results are checked
+psModules/src/imcombine/pmSubtraction.c -- results are checked
+psModules/src/imcombine/pmSubtractionMatch.c -- results are checked
+psphot/src/psphotMakeResiduals.c -- results checked
+psModules/src/objects/pmSourceMatch.c -- results checked (could handle nan better)
+psModules/src/detrend/pmSkySubtract.c -- unused code
+psModules/src/objects/models/pmModel_SGAUSS.c -- unused code
+}}}