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ukhandurrani
Level II

How to write your own non-linear model

I need to analyze my data using the Von Bertalanffy Growth function to my data (age vs Length). But I couldn’t figure out where and how to write my own non-linear regression model. Need help. My model is:

a*(1-exp(-(b*(age-c))))

1 ACCEPTED SOLUTION

Accepted Solutions
Jeff_Perkinson
Community Manager Community Manager

Re: How to write your own non-linear model

Take a look at the documentation for the Nonlinear platform. The first section walks through an example to show exactly how to do this.

 

In short, after creating the column with your formula and parameters you put that column in the X, Predictor Role and your response column in the Y role.

 

2021-06-22_11-47-24.286.png

 The example you've given is from the Fit Curve platform. The output from Nonlinear is similar, though not exactly the same.

-Jeff

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10 REPLIES 10
dale_lehman
Level VII

Re: How to write your own non-linear model

You can use the nonlinear platform (found under specialized modeling).  a, b, and c should be entered as parameters (you need to supply initial values) and the platform will fit your model to your data - if it converges.  If not, you might have to change your initial guesses for the parameters.  If you haven't done this before, instead of entering variables in your formula, change the drop down menu from Table Variables to parameters.

ukhandurrani
Level II

Re: How to write your own non-linear model

Thanks for the reply. Could you please check the attached screenshots; I did not get any results  JMP.pngJMP 2.PNG

ukhandurrani
Level II

Re: How to write your own non-linear model

Please have a look at this too: JMP3.PNG

dale_lehman
Level VII

Re: How to write your own non-linear model

In the nonlinear launch, you need to put your predictor formula as "predictor" not the age variable.

ukhandurrani
Level II

Re: How to write your own non-linear model

Hi
I followed these steps: Analyze => Nonlinear =>  Model Library => Gompertz model (it is similar to my equation) => Selected Y and X from  my data => then in my  spreadsheet a new column is added and by double clicking on it a new windows open for editing formula. 

But I did not get any output results just like JMP own nonlinear regression  JMP1.PNGJMP 2.PNG

ukhandurrani
Level II

Re: How to write your own non-linear model

Hi again, 
I want to get output results similar to the attached screenshot from my equation (Von bertalanffy equation). ThanksResults.PNG

Jeff_Perkinson
Community Manager Community Manager

Re: How to write your own non-linear model

Take a look at the documentation for the Nonlinear platform. The first section walks through an example to show exactly how to do this.

 

In short, after creating the column with your formula and parameters you put that column in the X, Predictor Role and your response column in the Y role.

 

2021-06-22_11-47-24.286.png

 The example you've given is from the Fit Curve platform. The output from Nonlinear is similar, though not exactly the same.

-Jeff
ukhandurrani
Level II

Re: How to write your own non-linear model

Thanks for the hints. It works and got the results. But I did not get "Summary of Fit". I also need to get AIC, BIC, R2 etc. to check my model fitness. Thanks once again for the hints. JMP results.PNG

Chirag
Level I

Re: How to write your own non-linear model

Dear sir, But, how to get the prediction model and other results like the goodness of fit criteria result like AIC, AICC, BIC, SSE, MSE, RMSE, R-Square, parameter estimate + SE, wald chi-square p-value, upper and lower confidence intervals, 

as well as predicted and residual values, Correlation and Covariance of Estimates