A confusing lev-mar error

[jcrabtr]

I am trying to fit a Lorentzian to some acquired data using the lev-mar function, and it returns the error "wrong model equation". I know for a fact that the data has a lorentzian shape because I wrote a little vi to fit it manually using the exact same equation. Does anyone have a suggestion as to what to do next, or at least what the "wrong model equation" error really means? Thank you.

JPC

[Jonnie_5]

The error refers to a syntax issue with the "model description" input.

This input is a cluster of three strings: model, which is the actual equation (Ex: a+b*x+c*x^2); paramters, which are the solvable variables (a, b, & c in the previous ex.) inputted as an array of strings; and the independent variable (x).

All 3 parts of the model must match exactly (e.g. you can't have 3 variables in the model and 1 in the parameters, and if you designate x as the independent variable, there must be an x in the model equation).

Additionally, the model equation follows standard LabVIEW formula node syntax, except there are no input variables designated ("y=x+1" won't work but "x+1" will) and you don't need a semi-colon terminator.

Let me know how it goes,
~j5

[Jonnie_5]

The error refers to a syntax issue with the "model description" input.

This input is a cluster of three strings: model, which is the actual equation (Ex: a+b*x+c*x^2); paramters, which are the solvable variables (a, b, & c in the previous ex.) inputted as an array of strings; and the independent variable (x).

All 3 parts of the model must match exactly (e.g. you can't have 3 variables in the model and 1 in the parameters, and if you designate x as the independent variable, there must be an x in the model equation).

Additionally, the model equation follows standard LabVIEW formula node syntax, except there are no input variables designated ("y=x+1" won't work but "x+1" will) and you don't need a semi-colon terminator.

Let me know how it goes,
~j5