Fix CL Quant Error

[k8macarthur]

Previously the following code would produce different composition values in the EDX quantification.

import hyperspy.api as hs
import numpy as np
def get_composition(intensities, xray_lines, kfactors, thickness):
    spc = hs.signals.EDSTEMSpectrum(np.array([0]))
    signals = []
    for index, intensity in enumerate(intensities):
        signal = hs.signals.BaseSignal(np.array([intensity]))
        signal.metadata.add_node('Sample')
        xray_line = xray_lines[index]
        element = xray_line[:-3]
        signal.metadata.Sample.elements = [element]
        signal.metadata.Sample.xray_lines = [xray_line]
        signals.append(signal)
        
    results = spc.quantification(intensities=signals, method='CL', factors=kfactors, absorption_correction=True, thickness=thickness)
    atomic_percents = [result.data[0] for result in results[0]]
    return atomic_percents

get_composition([1000, 180], ['Al_Ka', 'N_Ka'], [1.040, 2.547], 100)

get_composition([180, 1000], ['N_Ka', 'Al_Ka'], [2.547, 1.040], 100)

This pull request aims to fix that and add a unit test to check for this error in the future.

[codecov]

Codecov Report

Merging #2681 (0d0ee4c) into RELEASE_next_patch (4d6e0ed) will increase coverage by 0.35%.
The diff coverage is 100.00%.

@@                  Coverage Diff                   @@
##           RELEASE_next_patch    #2681      +/-   ##
======================================================
+ Coverage               76.30%   76.66%   +0.35%     
======================================================
  Files                     202      201       -1     
  Lines                   29641    29666      +25     
  Branches                 6473     6495      +22     
======================================================
+ Hits                    22619    22743     +124     
+ Misses                   5238     5168      -70     
+ Partials                 1784     1755      -29     

Impacted Files	Coverage Δ
hyperspy/misc/eds/utils.py	86.09% <100.00%> (ø)
hyperspy/_components/skew_normal.py	88.77% <0.00%> (-0.95%)	⬇️
hyperspy/misc/test_utils.py	88.13% <0.00%> (-0.38%)	⬇️
hyperspy/_components/lorentzian.py	97.05% <0.00%> (-0.35%)	⬇️
hyperspy/_components/gaussian.py	97.10% <0.00%> (-0.27%)	⬇️
hyperspy/misc/eels/tools.py	41.61% <0.00%> (-0.25%)	⬇️
hyperspy/io_plugins/protochips.py	95.34% <0.00%> (-0.08%)	⬇️
hyperspy/model.py	80.33% <0.00%> (ø)
hyperspy/samfire.py	64.10% <0.00%> (ø)
hyperspy/component.py	85.02% <0.00%> (ø)
... and 48 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 4d6e0ed...0d0ee4c. Read the comment docs.

[ericpre]

Thanks for the quick fix! This looks good, except one comment. It would be good to add a test covering the line highlighted by the codecov annotation.

[ericpre]

Corresponding discussion on https://gitter.im/hyperspy/hyperspy?at=60509e66e8267a46f21b103b