Curve fitting tool Fityk [fi:tik] is a program for data processing and nonlinear curve fitting. Primarily used: 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. Additional information: Developer: Marcin Wojdyr License: GPL-2.0-or-later Version: v1.3.1