Fityk [fi:tik] is a program for data processing and nonlinear curve fitting.
- by scientists who analyse data from powder diffraction, chromatography, photoluminescence and photoelectron spectroscopy, infrared and Raman spectroscopy, and other experimental techniques,
- to fit peaks – bell-shaped functions (Gaussian, Lorentzian, Voigt, Pearson VII, bifurcated Gaussian, EMG, Doniach-Sunjic, etc.),
but it is suitable for fitting any curve to 2D (x,y) data.
- intuitive graphical interface (and also command line interface),
- support for many data file formats, thanks to the xylib library,
- dozens of built-in functions and support for user-defined functions,
- equality constraints,
- fitting systematic errors of the x coordinate of points (for example instrumental zero error or sample displacement correction in powder diffraction),
- manual, graphical placement of peaks and auto-placement using peak detection algorithm,
- various optimization methods (standard Marquardt least-squares algorithm, Genetic Algorithms, Nelder-Mead simplex),
- handling series of datasets,
- automation with macros (scripts) and embedded Lua for more complex scripting
- the accuracy of nonlinear regression verified with reference datasets from NIST,
- an add-on for powder diffraction data (Pawley refinement)
- modular architecture,
- open source licence (GPLv2+).
In an attempt to make this software self-sustaining and actively developed in the future, new binaries are available to subscribers only:
MS Windows: fityk-1.3.1-setup.exe $
Mac OS X (10.6 or later): fityk-1.3.1-osx.zip $
Linux: binary RPM and deb packages for about 10 distros (incl. Ubuntu, Fedora, Suse), 32- and 64-bit.
Subscribers have access to all versions of the program and to e-mail support. The program can be installed on many computers and can be also used after the end of subscription.
- 1 month subscription: $115 (≈ €90)
- 1 year subscription: $199 (≈ €150)
- 2 years subscription: $299 (≈ €225)
Fityk is usually bought by companies and institutions. If you’re a home user or a student in an institution that won’t buy software for you - email firstname.lastname@example.org for info about discount.
- Manual (chapters Introduction, Getting Started, Data, Models, Curve Fitting, scripts, All the Rest).
- PDF, ePUB and older versions of the manual can be downloaded from Read the Docs.
- Fityk Wiki (you are welcome to contribute).
Feel free to send questions, comments, requests, bug reports, and success stories. Asking for a new feature usually results in adding the request to the TODO list or, if it already is in the list, in assigning higher priority to it.