Cubic Surface using regress function

[john_clark]

I have used the "regress" function to generate a cubic surface for a set of data and have plotted the results.

The regress function provide a vector with the coefficients for the surface polynomial. However it does not specify the variable names for each coefficient. I need to know the variable names for a paper I am writing.

Also is there a standard format for the form of a polynomial equation generated by MCAD for other polynomial degrees ??

See attached file

Thanks

John Clark
www.clark-engineeers.com

[RichardJ]

On 1/20/2009 10:08:09 AM, john_clark wrote:
>I have used the "regress"
>function to generate a cubic
>surface for a set of data and
>have plotted the results.
>
>The regress function provide a
>vector with the coefficients
>for the surface polynomial.
>However it does not specify
>the variable names for each
>coefficient. I need to know
>the variable names for a paper
>I am writing.

Go to "Quicksheets", "Data Analysis", "Using regress: Multivariate Regression". It describes the order of the coefficients.

>Also is there a standard
>format for the form of a
>polynomial equation generated
>by MCAD for other polynomial
>degrees ??

There is no standard order for the coefficients for a polynomial with more than one independent variable.

Richard

[ptc-1368288]

>Also is there a standard format for the form of a polynomial equation generated by MCAD for other polynomial degrees ?? <<br> _______________________

If that's what you mean: the standard order of the bivariate coefficients follows the format of the "Quadrics". I won't swear on that, my version (11.2a) does not open your *.XMCD.

jmG

[ValeryOchkov]

May be so - see the attached file
Val
http://twt.mpei.ac.ru/ochkov/v_ochkov.htm