[C2E] Calibration throwing FFT error

[Samuel Jackson]

Reported by Vicky. Running the file OSIRIS00102537.raw causes mantid to throw a top level exception as it can't find the expected workspaces and spits out the following error from FFTSmooth:

Error in execution of algorithm RealFFT:
X axis must be linear (all bins have same width). This can be ignored if IgnoreXBins is set to true.
Error in direct FFT algorithm
Error in execution of algorithm FFTSmooth:
X axis must be linear (all bins have same width). This can be ignored if IgnoreXBins is set to true.
ValueError: X axis must be linear (all bins have same width). This can be ignored if IgnoreXBins is set to true.
  at line 8 in '<Interface>'
  caused by line 66 in '/home/chs18285/git/mantid/Code/Mantid/scripts/Inelastic/IndirectEnergyConversion.py'
  caused by line 482 in '/home/chs18285/git/mantid/Code/Mantid/scripts/reduction/reducer.py'
  caused by line 479 in '/home/chs18285/git/mantid/Code/Mantid/scripts/Inelastic/inelastic_indirect_reduction_steps.py'
  caused by line 524 in '/home/chs18285/git/mantid/Code/Mantid/scripts/Inelastic/inelastic_indirect_reduction_steps.py'
  caused by line 561 in '/home/chs18285/git/mantid/Code/debug/bin/mantid/simpleapi.py'

[Samuel Jackson]

Raw file that causes the crash

[Samuel Jackson]

Refs #8512 Set FFTSmooth to use IgnoreXBins option.

Changeset: 1547b26e4076754788a4804c914c0c1284608d71

[Samuel Jackson]

Refs #8512 Add better error handling when using an invalid workspace.

Changeset: e90a1b39c9850231f83c05b64176f0dd5cbf3746

[Samuel Jackson]

After discussion with Spencer, this should be the case because Indirect C2E doesn't work with workspaces with uneven bin widths. I've added a more verbose error message and prevented the top level exception from occurring.

To Test:

• Open the supplied file in the Calibration tab of Indirect C2E and check the error message.
• Check that no top level exception was thrown.
• Code inspection of the changes.

[Gesner Passos]

I think the GUI should rise a QMessage::Warning informing that it failed and the reason why it has failed.

Currently we get the following log message:

Error in execution of algorithm RealFFT:
X axis must be linear (all bins have same width). This can be ignored if IgnoreXBins is set to true.
Error in direct FFT algorithm
Error in execution of algorithm FFTSmooth:
X axis must be linear (all bins have same width). This can be ignored if IgnoreXBins is set to true.
Indirect Energy Conversion does not support uneven bin widths.

The user does not have access to IgnoreXBins option. Hence, the only information that is important to him is:

Indirect Energy Conversion does not support uneven bin widths.

But, a widget raising to tell the user would be better. At least from my point of view.

[Samuel Jackson]

Refs #8512 Add better error message.

Changeset: 637d189a96e8448aa23070e8dfe71cfbc92e4100

[Samuel Jackson]

Refs #8512 Updated error message.

Changeset: fbb3bad30a0ba95045db22b24ba551ae22567d63

[Peter Parker]

Merge remote-tracking branch 'origin/bugfix/8512_C2E_FFT_error'

Full changeset: ​5878e6fd1d73764047cfad14ad15957c23ea5b4e

[Peter Parker]

Warning message is now presented to user when uneven bin widths are encountered.

[Stuart Campbell]

This ticket has been transferred to github issue ​9356