Thanks very much it solved my problem. cheers, Amit
On Sun, Dec 20, 2009 at 7:56 PM, David Winsemius <dwinsem...@comcast.net> wrote: > > On Dec 20, 2009, at 1:35 PM, Amit wrote: > >> Dear All, >> I am trying to plot polynomial regression line to a scatterplot. I did >> following so far: >> >>> x=c(1:9335) >>> y=read.table("gp.txt",header=T,sep="\t") >>> length(y$PCC) # y$PCC has values between 1 to 0 in decreasing order >> >> [1] 9335 >>> >>> plot(x,y$PCC,col="red") #scatterplot between x and y$PCC >>> reg=lm(y$PCC~poly(x,6)) # calculating polynomial fit with degree 6 >>> abline(reg,col="blue") >> >> Warning message: >> In abline(reg, col = "blue") : >> only using the first two of 7regression coefficients >> >> After the above warning a line is drawn in the graph parallel to the >> y-axis. But I was expecting a curve line through the scatterplot. >> Am I doing something wrong? Please help! > > abline is designed to draw lines of the form y=a+bx, ... hence the name. > (And as documented on its help page for regression objects). > > An effective method would be with lines and predict: > > plot(cars, main="Stopping Distance versus Speed") > lines(cars$speed, predict(lm(dist~poly(speed, 6) ,data=cars) ), col="red") > >> >> Best >> Amit >> >> _______________ > > David Winsemius, MD > Heritage Laboratories > West Hartford, CT > > ______________________________________________ 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.