Extend FitMethod option for CalculateTransmission

[Gesner Passos]

Current FitMethod can be Linear or Log.

Extend the list to: Linear, Log, Poly2, Poly3, Poly4, Poly5, Poly6.

Use the polynomial fit to fit for these options.

[Gesner Passos]

Introduction of PolyX fit function to CalculateTransmission

re #7734

Changeset: 74c420da807498e1c1f371b347ac36d60739a607

[Russell Taylor]

Re #7734. Resolve overload ambiguity on the Mac.

Changeset: b297661008f981a70dd1e7c534911bb202c8b8f3

[Gesner Passos]

Change the CalculateTransmission parameter

Instead of having the FitMethod with PolyX, change it to Polinomial and add a new parameter PolynomialOrder to set up the order.

It may solve the building tests problem in mac os

re #7734

Changeset: e3d8fbe89facf52ae353367bd9ec1dd10effda1e

[Gesner Passos]

Fix CalculateTransmission in mac os

Adding Levenberg-MarquardtMD minimizer to polynomial fit solves the issue of breaking the unit test inside mac os - snow leopard.

re #7734

Changeset: ccea205f4ffd3250fc30da96dd6ecc6f67dc6f4a

[Gesner Passos]

Tester

Below you have a code that allows you to test CalculateTransmission. Change the FitMethod and PolynomialOrder as you like and check that the result is nice (plot out and out_fitted).

from mantid.simpleapi import * 
#prepare data to the input of CalculateTransmission
ws = LoadRaw("LOQ48097.raw", SpectrumMin=1, SpectrumMax=2);
ws = ConvertUnits(ws, Target="Wavelength")
m_dirWS = Rebin(ws, "6, 0.01, 7.5",OutputWorkspace="CalculateTransmissionTest_direct")
m_transWS = Rebin(ws, "7.5, 0.01, 9",OutputWorkspace="CalculateTransmissionTest_trans")
m_dirWS.setX(0, m_transWS.dataX(0))
m_dirWS.setX(1, m_transWS.dataX(0))
out = CalculateTransmission(m_transWS, m_dirWS, 1, 2, RebinParams="7.5, 0.1, 9",FitMethod='Polynomial', PolynomialOrder=4,OutputUnfittedData=True)

[Jay Rainey]

Merge remote-tracking branch 'origin/feature/7734_polyn_trans_fit'

[Jay Rainey]

Testing

• The Fit method can now be a Polynomial as expected.
• Tested using the above script (comment:5) by switching parameters of FitMethod and PolynomialOrder to ensure it works for all possible cases (and doesn't work for erroneous cases).
• Tested on Ubuntu 12.04

Code review

• Well written code and comments.

[Stuart Campbell]

This ticket has been transferred to github issue ​8579