Curve fitting tool complex value computed by model function

David gordon

2017 7 17

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9 次查看（30 天）

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I am trying to use the Matlab Curve Fitting tool to fit a dataset to the Wiebe Function, x=b*(1-exp(-2.3026*((x-start)/duration)^(m+1))). Where x is the output variable, y is the input variable and b, start, and duration are the model fitting parameters. When I manually set m to any whole number I get a solution, however, if it is decimal or set to a parameter that the tool can vary I get the following error. "Complex value computed by model function, fitting cannot continue. Try using or tightening upper and lower bounds on coefficients."

I have also constrained the bound on 'm' to 1.1 to 1.2 and I still get the same error.

Any help resolving this issue would be greatly appreciated!