Motofit News

he GenOpt XOP enables IGOR Pro to use Genetic Optimization (more specifically Differential Evolution) to curvefit data.

Genetic Optimisation is a valuable technique for finding global best fits, as it is has a high probability of finding the best solution, even if the starting guesses for the fit are poor. In contrast other fitting techniques, such as Levenberg Marquardt, are gradient based, and can often fall into local minima if poor starting guesses are used.

An important bug fix has just been issued for the Genetic Optimisation package. This bug caused insufficient mutation in the guesses, which meant that global minima may not have been attained in some cases.

Amongst other things the new release contains an integrated scattering length density calculator, a historical record of all the fits performed (exportable as RTF) and Waveform support for genetic optimisation.

A GUI has been added to the genetic optimisation package. This makes it much easier to initialise fitting, although the command line functionality is still present.

Motofit can now use an external plugin, Abeles.xop, which speeds up calculation rates by a factor of 5. This makes Genetic Optimization the method of choice for refining neutron and X-ray reflectometry data.

THe latest versions of Motofit are now able to use genetic optimisation, which is a powerful tool for finding global minima in Chi2 functions.