Software package for numerical calculus, statistics, graphs and mathematical simulations


Simfit is a software package for simulation, curve fitting, statistical analysis and graphing. It use a collection of mathematical models or supplied by the user. Can be used in biology (growth curves), physiology (transport), pharmacology (dose-response curves), pharmacy (pharmacokinetics), immunology (ligand binding), biochemistry (calibration), biophysics (kinetic), epidemiology (analysis of survival), medical statistics (meta analysis), chemistry (chemical kinetics) and physical (dynamical systems).


  • Academic version
    It is fully operational, imports Excel data directly through the clipboard, and contains a manual along with numerous test files. This is the default Simfit configuration and is the most recommended for users. It is available in 32 and 64 bit.


  • NAG version
    It is actually the Academic version itself that is configured to use the numerical routines of the "NAG Library". To do this, it uses links between the dynamic link library w_maths.dll of the Academic version of Simfit and the dynamic link library of NAG. This configuration can only be used if the NAG DLLs are installed on the computer.

Distribution in English: The only distribution is the "Academic" version which is fully operational. This version has an executable file that allows swapping the mathematical libraries of the Academic SIMFIT to the mathematical libraries of the "Nag Library" and thus create a say "NAG version".

Distribution in Spanish: There is only the 32-bit academic version, which is the translation of version 5 of English (2008). It is kept for teaching purposes in Spanish, but for research the latest version in English is recommended, which is revised and expanded. This distribution is autonomous and free, with test files and documentation. includes an English manual in PostScript and PDF with index and hyperlinks. It is not recommended to link to the dlls of the NAG library.