Add non-linear peak fitting library to xmgrace

[feranick@…]

Last year support for non-linear Lorentian, Gaussian peak fitting was added to the debian port of grace. The associated bug report for debian is here:

​http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=578435

Since then the patch has been stabilized and it made into the most stable build of grace in debian. Ubuntu has it has well in the default build of grace. It would be great to implement it also here in macports. The patch which I originally wrote is attached here. I tested it on a local build, applied directly to the port of grace in OS X with no issues.

This is a rational for the patch:

"One of the most used features in software for scientific data analysis is the ability to perform non linear peak fitting (specifically Lorentzian and Gaussian fits). Xmgrace sorely lacks this capability, unless you consider adding manually the required formula.

The attached patch attempts to resolve this issue, by extending the non-linear panel with new menu entries (under a new "Library" menu entry) for:

Gaussian (single, double, chromatography), Lorentzian (single double), Pseudo Voigt 1, Pseudo Voigt 2, Asymmetric double sigmoidal, Log Normal Function, Gram-Charlier A-Series, Edgeworth-Cramer Series, Inverse Polynomial Function.

It also includes, Periodic Peak functions (Sine, Sine square, Sine damp), and Baseline Functions (Exponential Decay 1, Exponential Decay 2, Exponential Growth 1, Exponential Growth 2, Hyperbolic, Bradley, Logarithm 3 parameters).

[mf2k (Frank Schima)]

Is this still relevant for grace 5.1.25?

[feranick@…]

Yes, it is still definitively relevant. It was never applied upstream, while Debian included it several years back (see Debian bug report in the link above).