Global Fitting by Olis

A Revolutionary Approach to Kinetic Analysis

The primary emphasis thus far has been on fitting stopped-flow data but the fitting should be applicable to other types of data. The newly developed global kinetic program has 3 major improvements over existing commercially available global fitting programs. These are: an improved factor analysis procedure, modified SVD; a much improved fitting engine, downhill simplex; and last but by no means least a greatly improved function evaluator, matrix exponentiation. Additionally the program is easy to use and highly optimized and consequently very fast.

Modified SVD

The classic Golub and Reinsch singular value decomposition algorithm has been optimized for the kinetic problem in hand. Proprietary modifications to the algorithm yield an up to 3 orders of magnitude speed increase and an approximately 3-fold improvement in standard deviation. (Click here for more on factor analysis.)

Downhill Simplex

The simplex algorithm of Nelder and Mead replaces the usual Levenberg-Marquardt method as the non-linear fitting engine. The simplex method shows much better convergence properties, i.e. is much less prone to finding false minima. It is also relatively more tolerant of 'bad' starting values. (Click here for more information on simplex.)

Matrix Exponentiation

All sequences of, or combinations of, first order processes can be expressed as a differential equation set. The rate constants form a square matrix. When matrix exponentiation is applied to such a matrix an exact and direct solution of the system is obtained. The beauty of matrix exponentiation is that no algebraic solution of the differential equation set is required, it requires only the rate constant matrix. This is no small matter in the many species and many rate cases. (Click here for more information on matrix exponentiation.)

Convenience and Speed

Fit selections are made from menus covering over 40 cases by a single keystroke. The program is highly optimized for speed; and in combination with the ease of use makes it convenient and rapid in use.

Summary

The combined 3 major improvements confer a greatly increased capability on Olis global fitting compared to previous efforts. The novel combination of features constitutes a new global fitting paradigm; and is the way of choice for the new millennium.