Error in SplineWorkspace

[Russell Taylor]

The following code in SplineWorkspace.cpp (starting at line 88) came to my attention because coverity scan complained about dereferencing a null pointer:

  double* yValues(0);
  m_cspline->derivative1D(yValues, xValues, nData, 2);
  for(size_t i=0;i<nData;i++)
  {
    out->set(i,0,1.);
    out->set(i,1,xValues[i]);
    out->set(i,2,yValues[i]);
  }

yValues needs to be an array, but is not declared as such. The best approach here would be to declare it as a local std::vector and then pass its address to derivative1D.

Also, this class is lacking a unit test, which surely would have picked up this mistake.

Finally, calling a class *Workspace when it's a function is confusing! Could you come up with an alternative name please?

[Roman Tolchenov]

There are existing functions CubicSpline or BSpline and also algorithms SplineSmoothing and SplineInterpolation. Is SplineWorkspace a duplicate of one of them?

[Russell Taylor]

This work was done for Jose and he's not sure it is doing quite what he wants. He suggests removing the algorithm & function from master for the time being, which will happen in #8877. I won't remove the code, just comment out the registration.

[Vickie Lynch]

I am only using Roman's CubicSpline interpolation here to convolve spectra from two workspaces. I did not want to make SplineWorkspace a separate function, but Andrei insisted on this when he tested 8761. That is why there is not unit test. I have done testing of convolving two normalized Gaussians to prove that the answer for ConvolveWorkspaces is correct. I will discuss with Jose why this does not do what he wants.

[Vickie Lynch]

Refs #8850 remove SplineWorkspace

Changeset: eaad2e997e6102b7a84175b8fd54443d082435a2

[Vickie Lynch]

Refs #8850 put workspaces into AnalysisDataService for test

Changeset: f3887555c88eda44a332fcadd60d414a53515458

[Vickie Lynch]

Refs #8850 fix unit test

Changeset: e6619810bfaf891027618ce7c4bcf3c57a094bdc

[Vickie Lynch]

To test run ConvolveWorkspaces with attached file for both input workspaces.

[Russell Taylor]

It would be best if Jose tested this ticket.

[Jose Borreguero]

Merge remote-tracking branch 'origin/feature/8850_SplineWorkspace_error'

Full changeset: ​5ada934459a12d9d0920e1a529adae9b18ab8042

[Jose Borreguero]

Worked as expected

[Stuart Campbell]

This ticket has been transferred to github issue ​9694