Marginal effects from interaction regression model
On Jul 25, 2010, at 11:47 PM, Guillem R. wrote:
As far as I know, the predict command gives the predicted values (and intervals) of y, but what I'm looking for is the conditional effects (betas) of x on y conditional on values of z.
If you want the betas, then simply print the object. Don't for get the default parameterization is for treatment effects.
I'm trying to produce a plot similar to the first shown in this link: http://homepages.nyu.edu/~mrg217/interaction.html#code
If you want to provide an example ...and a more complete description of the desire output, I sure someone here can finish the job of showing you how setting up a call to predict will get you to that goal.
David. > > Thanks again > > > > David Winsemius wrote: >> >> >> On Jul 25, 2010, at 10:24 PM, Guillem R. wrote: >> >>> >>> Dear all, >>> >>> I'd like to plot the marginal effect of a variable in a >>> multiplicative >>> interaction regression, that is, the effect of a variable >>> conditional on the >>> values of another variable. As an illustration, given model lm1 >>> >>> lm1 <- lm(y ~ x*z) >> >> ? predict >> >> Perhaps: >> >> predict(lm1, newdata=data.frame(x=1:10, z=5), interval="confidence") >> >> >>> >>> I'd like to get the effects of x on y conditional on the values of >>> z, with >>> the corresponding confidence intervals if possible. Does anyone know >>> of any >>> package or simple way to do this? >>> >>> Thanks >> >> -- >> >> David Winsemius, MD >> West Hartford, CT >> >> ______________________________________________ >> R-help at r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide >> http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. >> >> > > -- > View this message in context: http://r.789695.n4.nabble.com/Marginal-effects-from-interaction-regression-model-tp2301858p2301884.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. David Winsemius, MD West Hartford, CT