The following variables have the following significant relationships (x is the explanatory variable): linear, cubic, exponential, logistic. The linear relationship plots without any trouble.
Cubic is the 'best' model, but it is not plotting as a smooth curve using the following code: cubic.lm<- lm(y~poly(x,3)) lines(x,predict(cubic.lm),lwd=2) How do I plot the data and the estimated curves for all of these regression models in the same plot? x <- c(62.5,68.5,0,52,0,52,0,52,23.5,86,0,0,0,0,0,0,0,0,0,0) y <- c(0.054,0.055,0.017,0.021,0.020,0.028,0.032,0.073,0.076,0.087,0.042,0.042,0.041,0.045,0.021,0.018,0.017,0.018,0.028,0.022) Thanks in advance. Rhonda Reidy [[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.