Custom inverse prediction for quadratic (and higher orders) models

[friedrich]

In the fit curve platform the option to have a inverse prediction is not available for quadratic models. It would be nice to add it. Of course if possible to include cubic and others it would be top.

[Sarah-Sylvestre]

Hi @friedrich, thank you for your suggestion! We have captured your request and will take it under consideration.

[SamGardner]

@friedrich thank you for your suggestion.  I have a follow up question.  With a quadratic or higher order polynomial model, there is a possibility that that the fitted function will not be monotonic, and for a given Y value there could be two possible inverse solutions.  How would you propose that situation be handled?  

[friedrich]

@SamGardner , would it be possible to have both solutions in the output ? Or the user may choose before if he wants the result for the 1st or 2nd solution ?

[QubitQueen100]

I agree this would be helpful! I ran a standard curve with x as concentration and y as fluorescence. I now would like to predict concentration when given RFU. A 3rd-order polynomial fits my data well. However, I have to enter the fluorescence value one at a time using this workaround: https://community.jmp.com/t5/Discussions/inverse-prediction-using-quadratic-model/m-p/221830#M44262

I agree with friedrich ^ that all solutions could be output, or user could choose to display all real number solutions.