Date: Thu, 1 Apr 1999 17:51:34 -0600 "Nichols, David" "SPSSX(r) Discussion" "Nichols, David" Re: Curve Estimation "S-Curve"

Correction: the natural log of Y is regressed on the reciprocal of the natural log of X.

David Nichols Principal Support Statistician and Manager of Statistical Support SPSS Inc.

> -----Original Message----- > From: Nichols, David [SMTP:nichols@spss.com] > Sent: Thursday, April 01, 1999 5:23 PM > To: SPSSX-L@UGA.CC.UGA.EDU > Subject: Re: Curve Estimation "S-Curve" > > All of the models fitted in CURVEFIT are actually linear models fitted to > the original or transformed data. The S model is Y=exp(B0+B1/X), so the > natural log of Y is regressed on the natural log of X. > > David Nichols > Principal Support Statistician and > Manager of Statistical Support > SPSS Inc. > > > -----Original Message----- > > From: Chris Wirtalla [SMTP:ronchito@WORLDNET.ATT.NET] > > Sent: Wednesday, March 17, 1999 4:48 PM > > To: SPSSX-L@UGA.CC.UGA.EDU > > Subject: Curve Estimation "S-Curve" > > > > Hello -- I am using Curve Estimation in 9.0 to compare the relationships > > between each of my independent variables against the dependent. For one > > particular ind. variable, the "S-Curve" model showed the greatest > strength > > in > > terms of R-squared. Is there a way that I can "insert" this S-curve > logic > > into a linear regression to check it out? For example, some of my other > > variables have been shown to have strong quadratic relationships. To > > account > > for this, I add the square of that variable into the linear regression. > > Is > > there a similar way that I can do this for the S-curve? > > > > Thanks, > > > > Chris Wirtalla > > > > -----------== Posted via Deja News, The Discussion Network ==---------- > > http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own

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