Divide error message is not clear

[Martyn Gigg]

The following script produces an error message in Divide.

FileName="POLREF00004711.raw"
Load(Filename=FileName,OutputWorkspace="_Raw")
ConvertUnits(InputWorkspace="_Raw",OutputWorkspace="_Raw",Target="Wavelength")
NormaliseByCurrent(InputWorkspace="_Raw",OutputWorkspace="_D")

Io=CropWorkspace('_D','Io',StartWorkspaceIndex=2,EndWorkspaceIndex=2)
I=CropWorkspace('_D','I',StartWorkspaceIndex=4)

I=mtd['I'];Io=mtd['Io']
R=I/Io

The message states

The sizes of the two workspaces (I_1: 242 spectra, blocksize 1000) and (Io_1: 1 spectra, blocksize 1000) are not compatible for algorithm Divide
Logic Error in execution of algorithm Divide
The sizes of the two workspaces (I_1: 242 spectra, blocksize 1000) and (Io_1: 1 spectra, blocksize 1000) are not compatible for algorithm Divide
Error in execution of algorithm Divide
Execution failed for the algorithm Divide

This looks like it should succeed but the actual problem is that the X values don't match for the input workspaces so a rebin is required. The current check for size compatability only returns a bool. It would better to return an error string and improve the error reporting in cases like this.

[Nick Draper]

Moved at end of release 2.1

[Nick Draper]

Moved at the end of release 2.2

[Nick Draper]

Moved to milestone 2.4

[Nick Draper]

Moved at the code freeze for release 2.4

[Nick Draper]

Moved to r2.6 at the end of r2.5

[Keith Brown]

Changed checkSizeCompatiblity to std::string to aid error usefulness

BinaryOperation::checkSizeCompatiblity and overridden versions in child classes have been changed to return std::string rather than bool so that a useful error message can be passed back down the call stack before finally being used in throwing std::invalid_argument in BinaryOperation::checkCompatibility. A return of true is now a return of "" (empty string). A return of false is now a string of length 1 or more containing an error about why the algorithm couldn't complete. Functions that used the bool return before have been changed to use checkSizeCompatiblity(lhs,rhs).empty as that is the equivelent of the old boolean return. Removed a load of commented-out code from Multiply.cpp. Indented WeightedMean.cpp and WeightedMean.h as per the guidelines.

Refs #4489

Changeset: 2ffcc5c5c2c255b69cec9d3dcd74a3598d638605

[Keith Brown]

Streamlined the error throwing and corrected some grammar

BinaryOperation::checkCompatibility no longer uses a stringstream and just throws the message reported by BinaryOperation::checkSizeCompatibility Some error messages were missing some punctuation. One error message was re-worded.

Refs #4489

Changeset: d7f563a67812f89fb4a75f4895e38e4480e418cf

[Keith Brown]

Tidied up some unneeded comments

Removed a block of commented out code from BinaryOperation.h

Refs #4489

Changeset: a3c2dab6efade1e10154ceda847ce2b074d5f11d

[Keith Brown]

I've checked all the functions with what data i have and they're throwing cleaner and producing more useful errors in the main log.

To Test: In the python script editor, apply all the functions that inherit from BinaryOperation on some workspaces that are known to throw errors on those functions. It is recommended, although optional, to try and get each to return all errors they could possibly return.

[Russell Taylor]

There's a gcc compiler warning needs fixing (BinaryOperation.cpp line 376): ​http://download.mantidproject.org/jenkins/job/is_inc_rhel6_develop/1253/warnings14Result/NORMAL/?

Just stick a pair of braces around the subsequent if-else

[Keith Brown]

Added braces to avoid a warning

Added a pair of braces near BinaryOperation.cpp line 376 to stop an if being ambiguous

Refs #4489

Changeset: 78d26f9e33fd53ab479448baefdde56f32a2547a

[Keith Brown]

Added the brackets. Checking build servers now

[Keith Brown]

To Test: In the python script editor, apply all the functions that inherit from BinaryOperation on some workspaces that are known to throw errors on those functions. It is recommended, although optional, to try and get each to return all errors they could possibly return.

[Keith Brown]

Here is the script i was using

FileName="C:/Users/FXQ83530/Mantid/systemtests/Data/POLREF00004699.raw" Load(Filename=FileName,OutputWorkspace="_Raw") ConvertUnits(InputWorkspace="_Raw",OutputWorkspace="_D",Target="Wavelength") #NormaliseByCurrent(InputWorkspace="_Raw",OutputWorkspace="_D")

Io=CropWorkspace(InputWorkspace='_D',OutputWorkspace='Io',StartWorkspaceIndex=2,EndWorkspaceIndex=2) I=CropWorkspace(InputWorkspace='_D',OutputWorkspace='I',StartWorkspaceIndex=4)

I=mtdI? Io=mtdIo? R=I/Io

[Samuel Jackson]

Merge remote-tracking branch 'origin/feature/4489_divide_error_improve'

[Samuel Jackson]

All operations appear to work fine and are producing more verbose strings.

[Stuart Campbell]

This ticket has been transferred to github issue ​5336