Is GNI sorted? if not then the lines function plots the line segments to the points in the order given and that would explain part of the strangeness (the png file did not make it through). Are there gaps between the GNI values? even if GNI is sorted, your code below will just draw line segments between values that GNI was observed at and not a smooth curve between them.
Better would be something like: xx <- seq( min(GNI), max(GNI), length.out=250 ) y.predict <- predict(y.loess, newdata=data.frame(GNI=xx)) lines(xx,y.predict) On Mon, Sep 24, 2012 at 2:58 AM, Maximilian Lklweryc <maxlklwe...@gmail.com> wrote: > Hi, > I have a scatter plot of the variables GNI and Lifeexp (Gross National > Income and Life Expectancy, both metric). So I plotted them and I want to > add a regression line and a lowess line. I use lowess and not loess because > I have missing values. My code: > plot(GNI,Lifeexp) > abline(lm(Lifeexp~GNI), col="red") > y.loess<-loess(Lifeexp~GNI,na. > action = na.exclude) > y.predict<-predict(y.loess) > lines(GNI,y.predict) > But when I do this (I get no error messages) the plot looks strange. The > lowess line is not a blue smoothy line, but it looks really strange, I > attached a png screenshot. > > Where is my mistake? Thanks a lot. > > [[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 ______________________________________________ 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.
