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Subject: Double exponential decay fit
Date: Wed, 14 Jan 2009 17:39:01 +0000 (UTC)
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Hi folks,
OK :
You have a set of data points (time,response) which correspond to a simple two exponential decay function (peak to baseline). 
You feed sigmaplot10 with it and using the simple equation y=a*exp(-bx)+c*exp(-dx) it gives you a nice fit. 
Now you do it in Matlab using the same data, same equation and on 2 out of 3 fit you've got a funny fit which obviously is wrong... 
Question:
Does anyone can explain the decrepancy between the two softwares? why sigmaplot10 can fit a simple two exponential decay function while Matlab doesn't?
Is there any issue with the method used? If so is there an alternative to make Matlab fit this simple two eponential decay function correctly?
Thanks for your help,
JS