Copy eigenvalues from D to omega when hermit=false and no mex

[RichardWaiteSTFC]

Testing Instructions

(1) Run this script (taken from Tutorial 19)

swpref.setpref('usemex', false);

FeCuChain = spinw;
FeCuChain.genlattice('lat_const',[3 8 4],'spgr','P 1')
FeCuChain.addatom('label','MCu2','r',[0 0 0])
FeCuChain.addatom('label','MFe2','r',[0 1/2 0])

FeCuChain.gencoupling
FeCuChain.addmatrix('label','J_{Cu-Cu}','value',1,'color','r')
FeCuChain.addmatrix('label','J_{Fe-Fe}','value',1,'color','b')
FeCuChain.addmatrix('label','J_{Cu-Fe}','value',-0.1,'color','orange')

FeCuChain.addcoupling('mat','J_{Cu-Cu}','bond',1)
FeCuChain.addcoupling('mat','J_{Fe-Fe}','bond',2)
FeCuChain.addcoupling('mat','J_{Cu-Fe}','bond',[4 5])
FeCuChain.genmagstr('mode','helical','S',[0 0;1 1;0 0],'k',[1/2 0 0])

spec = FeCuChain.spinwave({[0 0 0] [1 0 0] 21},'formfact',true,'hermit',false, ...
                          'fastmode', true);

f = figure('color','white');
ax = axes(f); box on; hold on;
plot(ax, spec.hkl(1,:), spec.omega,'marker', 'o')
xlabel(ax, "H (r.l.u.)")
ylabel(ax, "Energy (meV)")

It should produce this plot

Previously all eigenvalues were 0

Fixes #181

[github-actions]

Test Results

    4 files  ± 0    104 suites   - 2   8m 0s ⏱️ - 7m 23s
  684 tests  - 19    666 ✅  - 19  18 💤 ±0  0 ❌ ±0 
1 908 runs   - 38  1 872 ✅  - 38  36 💤 ±0  0 ❌ ±0 

Results for commit 2b98670. ± Comparison against base commit 74422b7.

This pull request removes 19 tests.

sw_tests.system_tests.systemtest_spinwave_symbolic_nips ‑ test_symbolic_general_hkl
sw_tests.system_tests.systemtest_spinwave_symbolic_nips ‑ test_symbolic_hamiltonian
sw_tests.system_tests.systemtest_spinwave_symbolic_nips ‑ test_symbolic_hamiltonian_squared
sw_tests.system_tests.systemtest_spinwave_symbolic_nips ‑ test_symbolic_hamiltonian_white
sw_tests.system_tests.systemtest_spinwave_symbolic_nips ‑ test_symbolic_spectra(test_spectra_function_name=sw_egrid)
sw_tests.system_tests.systemtest_spinwave_symbolic_nips ‑ test_symbolic_spectra(test_spectra_function_name=sw_instrument)
sw_tests.system_tests.systemtest_spinwave_symbolic_nips ‑ test_symbolic_spectra(test_spectra_function_name=sw_neutron)
sw_tests.system_tests.systemtest_spinwave_symbolic_nips ‑ test_symbolic_spectra(test_spectra_function_name=sw_omegasum)
sw_tests.system_tests.systemtest_spinwave_symbolic_nips ‑ test_symbolic_spectra(test_spectra_function_name=sw_plotspec)
sw_tests.system_tests.systemtest_spinwave_symbolic_nips ‑ test_symbolic_spectra(test_spectra_function_name=sw_tofres)
…

♻️ This comment has been updated with latest results.

[mducle]

Um, could you also remove lines 1163-1165 please? (I think I made a typo there and this supersedes it). Also maybe you can cherry pick the CI changes (commit 472e474c from the other PR and then merge this PR?

[RichardWaiteSTFC]

Um, could you also remove lines 1163-1165 please? (I think I made a typo there and this supersedes it). Also maybe you can cherry pick the CI changes (commit 472e474c from the other PR and then merge this PR?

The previous fix was causing tests to fail for hermit=true e.g.

================================================================================
  Error occurred in sw_tests.unit_tests.unittest_spinw_spinwave/test_fastmode(mex=char_old) and it did not run to completion.
      ---------
      Error ID:
      ---------
      'MATLAB:UndefinedFunction'
      --------------
      Error Details:
      --------------
      Unrecognized function or variable 'D'.
      
      Error in spinw/spinwave (line 1044)
              omega = D(1:nMagExt,:);
      
      Error in sw_tests.unit_tests.unittest_spinw_spinwave/test_fastmode (line 657)
                  spec1 = swobj.spinwave(hkl, 'fastmode', true);
  ================================================================================

So after this commit 5b5f4c2 I think I need to keep lines 1163-1165 (also from code looks like this will also be needed is using memory management loop).