lev mar parameter min value

[Peter_O'Connell]

When I use the Lev Mar curve fit, I get an error that says at least one of my input parameters is NaN or Inf.  There is a place in my fitting equation where I divide by the parameter and take the square root, so if it was either zero or negative, this would not work.

Is there a way that I could force Lev Mar to not choose values of 1 or zero for this parameter?  My initial guess is very small (on the order of 10^-4), but this parameter is time, so it should not be negative or zero anyways.

[altenbach]

What is your LabVIEW version? The function has been renamed to "nonlinear curve fit" many versions ago.

There is a constrained nonlinear curve fit that lets you set parameter bounds. Use that instead.

Can you show us your code and some typical data? If you calculate the model with your paramter guesses, does it look anything like the data?