The site linked above also includes access to a user-manual, Wiki, a journal, and FAQ's, (and I believe there is also support available via a user's forum). It compiles and runs on a wide variety of UNIX platforms, Windows and MacOS.
It is primarily used by scientists to analyze data from experiments (powder diffraction, chromatography, photoluminescence and infrared and Raman spectroscopy), but can be used to fit any analytical functions to any kind of data.
) and graphical techniques, and is highly extensible.One of R's strengths is the ease with which well-designed publication-quality plots can be produced, including mathematical symbols and formulae where needed.Īt the link provided above, you can access and download free software designed especially for statistical computing and data anaylysis. Fityk overview Fityk is user friendly, open source software for nonlinear curve fitting and data analysis. provides a wide variety of statistical (linear and nonlinear modelling, classical statistical tests, time-series analysis, classification, clustering. R is a language and environment for statistical computing and graphics. If you have an on-going need for the modeling and analysis of data, you might want to check out This option doesn't presume much in the way of users' knowledge relating to statistical anaylysis. You might also want to take a look at scikits-learn (another python package), Īccessible via the link, and free to download, with access to documentation.
You will have to install python, numpy and scipy. It's free and available on Windows, Linux and OS X.
The 'splines' library for R can be used for this.Īlso, let me give an honorable mention to python. Here, we get around the lack of knowledge about the overall functional form, by modelling the curve locally. Īnother idea is doing a spline regression. It takes a bit of computational time, but it will be attempting to build a formula for your data. The approach is based on genetic algorithms which do a symbolic regression. It uses artifical intelligence to guess what formula might be generating your data. If I understand your question correctly, you want to fit a function to your data, but you don't have any idea what family of functions to use.