Fityk is a curve fitting

Curve fitting

Curve fitting is the process of constructing a curve, or mathematical function, that has the best fit to a series of data points, possibly subject to constraints. Curve fitting can involve either interpolation, where an exact fit to the data is required, or smoothing, in which a "smooth" function...

 and data analysis application, predominantly used to fit analytical,
bell-shaped functions to experimental data.
It is positioned to fill the gap between general plotting software
and programs specific for one field, eg. crystallography or XPS

X-ray photoelectron spectroscopy

X-ray photoelectron spectroscopy is a quantitative spectroscopic technique that measures the elemental composition, empirical formula, chemical state and electronic state of the elements that exist within a material...

.

Originally, Fityk was developed to analyse powder diffraction

Powder diffraction

Powder diffraction is a scientific technique using X-ray, neutron, or electron diffraction on powder or microcrystalline samples for structural characterization of materials.-Explanation:...

 data.
It is also used in other fields that require peak analysis and peak-fitting, like chromatography

Chromatography

Chromatography is the collective term for a set of laboratory techniques for the separation of mixtures....

or various kinds of spectroscopy

Spectroscopy

Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative...

.

Fityk is distributed under the terms of GNU General Public License

GNU General Public License

The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....

,
but since version 1.0.0, subscription is required for downloading binaries.
It runs on Linux

Linux

Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

, Mac OS X

Mac OS X

Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...

, Microsoft Windows

Microsoft Windows

Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

, FreeBSD

FreeBSD

FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...

 and other platforms.
It operates either as a command line program or with a graphical user interface

Graphical user interface

In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...

.

It is written in C++, using wxWidgets

WxWidgets

wxWidgets is a widget toolkit for creating graphical user interfaces for cross-platform applications. wxWidgets enables a program's GUI code to compile and run on several computer platforms with minimal or no code changes...

, and providing bindings for Python and other scripting languages.

Features

• three weighted least squares methods:
  • Levenberg-Marquardt algorithm
    Levenberg-Marquardt algorithm
    In mathematics and computing, the Levenberg–Marquardt algorithm provides a numerical solution to the problem of minimizing a function, generally nonlinear, over a space of parameters of the function...
    
    ,
  • Nelder-Mead method
    Nelder-Mead method
    The Nelder–Mead method or downhill simplex method or amoeba method is a commonly used nonlinear optimization technique, which is a well-defined numerical method for twice differentiable and unimodal problems...
    
    
  • Genetic algorithm
    Genetic algorithm
    A genetic algorithm is a search heuristic that mimics the process of natural evolution. This heuristic is routinely used to generate useful solutions to optimization and search problems...
    
    
• about 20 built-in functions and support for user-defined functions
• equality constraints
• data manipulations,
• handling series of datasets,
• automation of common tasks with scripts.

Alternatives

The program peak-o-mat has similar scope.

More generic data analysis programs with spread-sheet capabilities include the proprietary Origin

Origin (software)

Origin is a proprietary computer program for interactive scientific graphing and data analysis. It is produced by OriginLab Corporation, and runs on Microsoft Windows...

 and its free clones QtiPlot

QtiPlot

QtiPlot is a platform-independent open-source cross-platform computer program for interactive scientific graphing and data analysis. It is similar to the proprietary programs Origin or SigmaPlot, and is being used to substitute these in universities ....

 and SciDAVis

SciDAVis

SciDAVis is a platform-independent open-source cross-platform computer program for interactive scientific graphing and data analysis...

.

External links

• Marcin Wojdyr, Fityk: a general-purpose peak fitting program, Journal of Applied Crystallography, 2010, Volume 43, pages 1126-1128