Free Curve Fitting Software for 4 Parameter Equation

[Ledsnyder]

Is there a software(preferably free) that can fit data into a 4 parameter equation?

like the generalised logistic function

 

[Sunfire]

TableCurve is great for the type of fitting you need, but it's not free... This is a good site where one can select operating system, rating etc. and look for curve fitting packages that are either free or shareware. There is a wide selection, so I am confident you will in high likelihood find what you need for free;

http://download.cnet.com/

 

[JJacquelin]

A method to fit to data the generalised logistic function (4 parameters) is given pages 42-43 in the document :
http://fr.scribd.com/doc/14674814/Regressions-et-equations-integrales

 

[gsal]

free? you can do it in python using the scipy module (scipy.optimize)...google "scipy curve fit", you should even find examples.

 

[pocketengineer]

Good source of information will span over many many years. Recently, I wanted to obtain a curve fitting equation from the given graph image / published graph. I felt so powerless to do so. This CurveFit Tracer may be helpful to some of you.

 

[Old Tele man]

Me thinks that maybe 'CurveFit Tracer' could be used to turn vacuum tube operating curves into useable mathematical equations! Has anybody tried this?