Click Finish button and the peak function is created and placed in PFW category. Setting bounds for each parameter will confine the fitted results in sensible range as show below:Ħ. Double click in cells in < or <= column(s) to toggle operators and then enter lower and upper bounds. Click Next button twice to go to Bounds and General Linear Constraints page. Enter function expression in Function Body edit box and do a quick check at x = 100 to make sure the expression is written correctly as shown below:ĥ. Click on each cell in Peak Attribute column to set peak attributes for each parameter. Click Next to go to Expression Function page. Click Next to go to Variables and Parameters page, input variables and parameters as shown below and check Peak Functioncheck box:Ĥ. Click Next to go to Name and Type page, select PFW category from Select or create a Category drop-down list, input MyPeakFunc as Function name.ģ. Hit F8 key or go to menu Tools: Fitting Function Builder to open Fitting Function Builder.Ģ. There are general 6 steps in defining a peak function:ġ. Where x is independent variable, y is dependent variable and parameters are as following: The peak function to be defined is expressed as below: Use defined peak function to fit peaks in Peak Analyzer.In this blog post we will discuss how to:
Fityk peak fitting how to#
We have put together an Origin Project (OPJ) User_Defined_Peak_Function.zip (5.8KB), you can download this OPJ file to learn how to defined a peak function and fit with it. And the first parameter must be named y0 (Offset). There should be at least four parameters in the defined peak function, that correspond to different peak characteristics, and assigned as attributes Offset/Baseline, Amplitude/Area, X Width, X Center. The defined peak function should be placed into PFW category and the Peak Function check box on The Variable and Parameter Page should be checked.Ģ. To summarize, Fityk is a comprehensive and efficient application that is meant to help users perform nonlinear data fitting using as a basis the results of experiments from numerous fields of scientific activity.In Origin, defining a peak function is very similar to defining an user-defined fitting function, but with two additional requirements to be met:ġ. The tool allows users to exclude inactivate points from fitting operations and work with several datasets simultaneously. Moreover, Fityk enables users to perform 'Power Diffraction Analysis' using 'X-Ray' or 'Neutron' radiation and various wavelengths ('Cu', 'Ag', 'Mo','Fe', etc). The utility allows users to execute a script, use data point 'Transformations' or adjust the preferred 'Functions', with the possibility of choosing between a wide range of options, such as 'Quadratic', 'Cubic', 'Gaussian', 'Lorentzian', 'EMG', 'Polyline', 'ExpDecay', 'Voigt', 'Spline', 'DoniachSunjic' and many more, while also letting users create their own. Users can work in 'Data Range', 'Add Peak' or 'Baseline' mode, according to their needs. The interface of Fityk is quite easy to understand, offering a toolbar for quick access to the most commonly used functions, as well as a menu bar, a main plot and a right-size panel where certain values can be edited.įityk provides users with several fitting methods, namely 'Levenberg – Marquardt', 'Nelder - Mead Simplex' and 'Genetic Algorithm', which can be of use in multiple analysis. These require a bit of documentation before being able to work with them properly, as such it is less approachable for novice users, though the more advanced can certainly appreciate its complexity. The program is fairly simple to work with, requiring minimal levels of knowledge or experience with similar tools, yet it features a set of rather complex functions. It is aimed at experimental data resulted from a variety of domains, like chromatography, spectroscopy, crystallography and many others.
Fityk peak fitting software#
Fityk is an advanced and reliable software solution whose main purpose is to assist users in fitting data to nonlinear functions.