| does curvefit() work ? [message #4138] |
Fri, 28 April 1995 00:00 |
aki
Messages: 3
Registered: June 1994
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Junior Member |
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Hi
I have to fit a modell function to given data and thought curvefit() would be a nice tool for doing that. In order to test curvefit() I ran the examples given in the online help. And no surprise curvefit calculated the 'right' fit. However when I slightly changed one of the starting values the fit was way off. I am aware that curvefit() finds local minimae only, but for such a _simple_ example it should be able to converge to the proper fit.
Did anybody encounter similar problems with curvefit(). Is there a workaround? Or is there another general fitting routine around? ( I know that there is a routine curfit() in the user_contrib/windt directory, but that one is most similar to curvefit and does not work either ).
To be specific I used the example given in the online help for curvefit() under the math section. When I changed the starting value from a=[10.0,-0.1,2.0] to a=[.0,-0.1,2.0] the fit failed .....
Any help is appreciated,
Andreas
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