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Bivariate Equation Question

hockswender

Community Trekker

Joined:

Jul 9, 2012

Running the Bivariate Fit leads to the (numerically correct)result:
Absorbance = -0.506803 + 0.0005822*Wavenumber + 6.0486e-5*(Wavenumber-861.488)^2
This is problematic when comparing to other analysis programs.
Is it possible to have JMP not use "(Wavenumber-861.488)" and just use Wavenumber?
Why does JMP do this in the first place?

Thanks for any insight.

1 ACCEPTED SOLUTION

Accepted Solutions
M_Anderson

Staff

Joined:

Nov 21, 2014

Solution

JMP is centering the equation... There are a bunch of reasons for why it's doing this, but you can turn it off if you use the "fit special" option rather than "the polynomial..." option under the red triangle.  Just select the degree of the polynomial and uncheck "Centered Polynomial."

 

Best,

 

M

1 REPLY
M_Anderson

Staff

Joined:

Nov 21, 2014

Solution

JMP is centering the equation... There are a bunch of reasons for why it's doing this, but you can turn it off if you use the "fit special" option rather than "the polynomial..." option under the red triangle.  Just select the degree of the polynomial and uncheck "Centered Polynomial."

 

Best,

 

M