The abline function works fine for simple linear regression because there is only 1 line, but with multiple linear regression there are an infinite number of lines and you need to decide which to plot (or find a way to plot t he plane/hyperplane/surface/etc.).
One option is to use the Predict.Plot and TkPredict functions in the TeachingDemos package. These will plot the relationship between the response and 1 of the predictors conditioned on values of the other predictors. On Wed, Feb 13, 2013 at 3:02 PM, Craig O'Connell <craigpoconn...@gmail.com>wrote: > Hello, > > My name is Craig and I need help plotting a "line" for a multiple linear > regression in R. > > Here is my sample data (filename: convis.txt) > > Output of convis.txt is (vis and density being predictors of either > avoidance or entrance): > > vis den avoid entrance > 1 10 1 0.0000 0.0000 > 2 10 3 0.8750 0.0000 > 3 8 3 0.8180 0.0300 > 4 8 3 0.6670 0.0667 > 5 8 1 0.2110 0.0000 > 6 6 1 0.2500 0.0000 > 7 10 1 0.3000 0.0000 > 8 10 1 0.1050 0.0000 > 9 8 1 0.7000 0.1000 > 10 3 5 0.1176 0.0588 > 11 3 5 0.3077 0.1150 > 12 3 9 0.9090 0.0900 > 13 3 7 0.7778 0.1110 > 14 3 5 0.5560 0.1110 > 15 3 1 0.5710 0.0000 > 16 3 4 0.5710 0.0000 > > In order to do the multiple regression, I used the following coding: > > > double=read.table("convis.txt",header=TRUE) > attach(double) > double > stem(vis) > stem(den) > stem(avoid) > stem(entrance) > plot(entrance,vis*den) *as means to see how the interaction between > visibility and density may impact entrance behaviors > model6=lm(entrance~vis*den) > model6 > summary(model6) > *abline(model6) *Here is the issue as I used this for my simple linear > regression technique, but do not know what to use for a multiple > regression* > > If anybody can provide some feedback on this, it would be greatly > appreciated. > > Kind Regards, > > Craig > > -- > <>< <>< <>< > Craig O'Connell > University of Massachusetts Dartmouth > Marine Biologist > www.youtube.com/craigpoconnell > craigosea.blogspot.com > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@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. > -- Gregory (Greg) L. Snow Ph.D. 538...@gmail.com [[alternative HTML version deleted]] ______________________________________________ R-help@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.