Product: TIBCO Spotfire®
How to specify raw polynomials in Spotfire's Linear Regression feature?
How to specify use of raw polynomials (instead of orthogonal polynomials) in Spotfire's Linear Regression feature?
A Spotfire user of the "Tools > 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)
There is no point-and-click way to modify the "raw" argument's default value.
The Linear Regression feature uses a built-in Spotfire data function that runs a TIBCO Enterprise Runtime for R (TERR) script.
In the Spotfire desktop client, selecting "Tools > TERR Tools > Launch TERR Console" will open a TERR Console session in its own window.
In the TERR Console session, the following (case sensitive) commands will open TERR online help topics for TERR functions that are used by the Linear Regression feature:
?lm
?formula
?poly