Description | Perl tools for X-ray Absorption Spectroscopy |
Demeter::PeakFit::LineShape - A lineshape object for peak fitting in Demeter
This documentation refers to Demeter version 0.9.26.
These are Fityk's built in lineshapes. Note that the format of this document section is parsed by the reporting methods of this object.
a
a0 + a1 * x
a0 + a1*x + a2*x^2
a0 + a1*x + a2*x^2 + a3*x^3
a0 + a1*x + a2*x^2 + a3*x^3 + a4*x^4
a0 + a1*x + a2*x^2 + a3*x^3 + a4*x^4 + a5*x^5
a0 + a1*x + a2*x^2 + a3*x^3 + a4*x^4 + a5*x^5 + a6*x^6
height*exp(-ln(2)*((x-center)/hwhm)^2)
if x < center then Gaussian(height, center, hwhm1)else Gaussian(height, center, hwhm2)
height/(1+((x-center)/hwhm)^2)
height/(1+((x-center)/hwhm)^2*(2^(1/shape)-1))^shape
if x < center then Pearson7(height, center, hwhm1, shape1) else Pearson7(height, center, hwhm2, shape2)
height*((1-shape)*exp(-ln(2)*((x-center)/hwhm)^2)+shape/(1+((x-center)/hwhm)^2))
convolution of Gaussian and Lorentzian #
convolution of Gaussian and Lorentzian #
a*c*(2*pi)^0.5/(2*d) * exp((b-x)/d + c^2/(2*d^2)) * (abs(d)/d - erf((b-x)/(2^0.5*c) + c/(2^0.5*d)))
h * cos(pi*a/2 + (1-a)*atan((x-E)/F)) / (F^2+(x-E)^2)^((1-a)/2)
...#
height*exp(-ln(2)*(ln(2.0*asym*(x-center)/width+1)/asym)^2)
cubic spline #
linear interpolation #
a*exp(-x/t)
Gaussian(area/hwhm/sqrt(pi/ln(2)), center, hwhm)
LogNormal(sqrt(ln(2)/pi)*(2*area/width)*exp(-asym^2/4/ln(2)), center, width, asym)
Lorentzian(area/hwhm/pi, center, hwhm)
Pearson7(area/(hwhm*exp(lgamma(shape-0.5)-lgamma(shape))*sqrt(pi/(2^(1/shape)-1))), center, hwhm, shape)
GaussianA(area*(1-shape), center, hwhm) + LorentzianA(area*shape, center, hwhm)
x < center ? Lorentzian(height, center, hwhm1) : Lorentzian(height, center, hwhm2)
x < center ? PseudoVoigt(height, center, hwhm1, shape1) : PseudoVoigt(height, center, hwhm2, shape2)
x < center ? Voigt(height, center, hwhm1, shape1) : Voigt(height, center, hwhm2, shape2)
These are lineshapes defined by Demeter
step*[atan((x-E0)/width)/pi + 0.5]
step*(erf((x-e0)/width) + 1)
See Demeter::Config for a description of the configuration system.
Demeter's dependencies are in the Build.PL file.
Need better aliasing of parameter names for add and reporting.
Please report problems to the Ifeffit Mailing List (http://cars9.uchicago.edu/mailman/listinfo/ifeffit/)
Patches are welcome.
Bruce Ravel, http://bruceravel.github.io/home
http://bruceravel.github.io/demeter/
Copyright (c) 2006-2018 Bruce Ravel (http://bruceravel.github.io/home). All rights reserved.
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See perlgpl.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.