Implement fit function back-to-back exponential convoluted with psuedo voigt

[Wenduo Zhou]

Implement a fit function back to back exponential convoluted with pseduo-voigt as an extension of existing fit function BackToBackExponential, which only is convoluted with Gaussian

[Wenduo Zhou]

Starting to implement BackToBackExponentialPV. Refs #8744.

Starting to implement BackToBackExponentialPV. The code is migrated from BacktoBackExponential. Some changes have been implemented. But it is not finished yet.

Changeset: 6659add48e23af00adbb5ab6e9813b908577517e

[Nick Draper]

Moved to backlog at the end of Release 3.1

[Wenduo Zhou]

Finished implementation of the function. Refs #8744.

Changeset: 936c2afb7d6e288c3b0019b8ffe42f6763fa3dc3

[Wenduo Zhou]

Added some unit tests. Refs #8744.

Changeset: eba451ac65d035f75ee4427f997677740ee04d7c

[Wenduo Zhou]

Fixed unit test. Refs #8744.

Changeset: f5e62cc79198ec9baac39407ac5b3eac9fde9024

[Wenduo Zhou]

Modified doc in wiki. Refs #8744.

Changeset: 3e4d8f8c7ee383199ee3feb641d8a36ccd231ba3

[Wenduo Zhou]

Added one more unit test. Refs #8744.

Changeset: 97afd4eb4ac552cf6e3bb9714c3b3e21d59789f0

[Wenduo Zhou]

Minor modification on how to calculate peak extent. Refs #8744.

Changeset: e204f6b76b4ecc882156cc5ce5853a693319c5bc

[Wenduo Zhou]

For tester

Find some data from instruments using back-to-back exponential convoluted with pseudo-voigt as peak profile. Then using this function to fit some peak.

[Anders Markvardsen]

ISIS HRPD focused processed nexus file

[Anders Markvardsen]

1. Load attached hrp55500.nxs file

2. Plot workspace hrp55500_2 for example

3. Add LinearBackground and one BackToBackExponentialPV peak

When I try to adjust the width graphically I get the error message "Peak width cannot be equal or less than zero", see attaced picture1.png

In another attempt, good new is that I did get a fit, but the parameters ! and B does not change. Also if I change the values of these manually as far as I can tell the peak shape does not change when I do plot guess.

When I select a non-zero value for Gamma, e.g. 1.0, and then to a fit I, the fit takes a lot longer and a lot of red lines are outputted, e.g:

rying to set a NaN or infinity value (1.#QNAN) to parameter Gamma Trying to set a NaN or infinity value (1.#QNAN) to parameter I Trying to set a NaN or infinity value (1.#QNAN) to parameter A Trying to set a NaN or infinity value (1.#QNAN) to parameter B Trying to set a NaN or infinity value (1.#QNAN) to parameter X0 Trying to set a NaN or infinity value (1.#QNAN) to parameter S Trying to set a NaN or infinity value (1.#QNAN) to parameter Gamma Trying to set a NaN or infinity value (1.#QNAN) to parameter I Trying to set a NaN or infinity value (1.#QNAN) to parameter A Trying to set a NaN or infinity value (1.#QNAN) to parameter B Trying to set a NaN or infinity value (1.#QNAN) to parameter X0 Trying to set a NaN or infinity value (1.#QNAN) to parameter S Trying to set a NaN or infinity value (1.#QNAN) to parameter Gamma Trying to set a NaN or infinity value (1.#QNAN) to parameter I Trying to set a NaN or infinity value (1.#QNAN) to parameter A Trying to set a NaN or infinity value (1.#QNAN) to parameter B Trying to set a NaN or infinity value (1.#QNAN) to parameter X0 Trying to set a NaN or infinity value (1.#QNAN) to parameter S Trying to set a NaN or infinity value (1.#QNAN) to parameter Gamma Trying to set a NaN or infinity value (1.#QNAN) to parameter I Trying to set a NaN or infinity value (1.#QNAN) to parameter A Trying to set a NaN or infinity value (1.#QNAN) to parameter B Trying to set a NaN or infinity value (1.#QNAN) to parameter X0 Trying to set a NaN or infinity value (1.#QNAN) to parameter S Trying to set a NaN or infinity value (1.#QNAN) to parameter Gamma Trying to set a NaN or infinity value (1.#QNAN) to parameter I Trying to set a NaN or infinity value (1.#QNAN) to parameter A Trying to set a NaN or infinity value (1.#QNAN) to parameter B Trying to set a NaN or infinity value (1.#QNAN) to parameter X0 Trying to set a NaN or infinity value (1.#QNAN) to parameter S Trying to set a NaN or infinity value (1.#QNAN) to parameter Gamma Trying to set a NaN or infinity value (1.#QNAN) to parameter I Trying to set a NaN or infinity value (1.#QNAN) to parameter A Trying to set a NaN or infinity value (1.#QNAN) to parameter B Trying to set a NaN or infinity value (1.#QNAN) to parameter X0 Trying to set a NaN or infinity value (1.#QNAN) to parameter S Trying to set a NaN or infinity value (1.#QNAN) to parameter Gamma Trying to set a NaN or infinity value (1.#QNAN) to parameter I

[Nick Draper]

Moved to the backlog at the code freeze of R3.3

[Stuart Campbell]

This ticket has been transferred to github issue ​9588