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Spotfire Ideas Portal
Status Future Consideration
Product Spotfire
Categories Analytics
Created by Guest
Created on Nov 6, 2017

Regression modeling - poly() function requires adding raw=TRUE

This should be an option under Regression Modeling so as not to require R programming experience in the use of the poly() function. Have seen similar problem from other users under TIBCO Community, I posted this same fix below after I researched the R function poly(). Quote from a Support Case:

A Spotfire user of the Linear Regression feature who wants 'poly()' coefficients that correspond directly to the x, x^2, x^3, etc. model components needs to specify 'poly(.., raw = TRUE )' in the formula the user provides in the Regression dialog's Formula field.

Using syntax like this:

     poly(`X1`, degree = 2, raw = TRUE)

in place of this:

     poly(`X1`, degree = 2)