FuncFit parameters not varying

Posts: 1
Joined: 2015-11-05
Location: United States

I have written a user-defined fitting routine to process my data. When I tried to update the code, it no longer works. I get a fit result but none of the parameters that are supposed to float actually do. When I look at the M_iterates iteration matrix the chi squared values are either zero, 1E-313 or -1. Does anyone have any ideas what would cause this? It appears that all of my inputs are good and the code takes time to fit but doesn't vary at all.

Posts: 1966
Joined: 2007-06-29
Location: United States

Maybe you need a epsilon wave. To learn more, copy this command, paste it into Igor's command line, and press Enter: DisplayHelpTopic "The Epsilon Wave"

There are lots of other possibilities. To have much chance of being able to help you, we would need more details, and possibly your code and an example data set. And, of course, instruction to make it run.

John Weeks
WaveMetrics, Inc.

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