X=read.table('ChlorellaGrowth.txt') X=as.matrix(X) Light=X[,1] rmax=X[,2] par(cex=1.5,cex.main=0.9) plot(Light,rmax,xlab="Light intensity (uE/m2/s)", ylab="Maximum growth rate rmax (1/d)",pch=16) # xlab and ylab are x and y axis labels, pch is "plotting character" # cex is 'character expansion' - cex=1.5 increases symbol & label sizes by 50% # cex.main sets the character expansion for the main title of the plot title(main="Data from Fussmann et al. (2000) system") fit=lm(rmax~Light) summary(fit); abline(fit) # Next we get the regression equation to 'display itself' on the graph c1=round(fit$coef[1],digits=3) # intercept c2=round(fit$coef[2],digits=3) # slope text(50,3,paste("rmax=",c1,"+",c2,"Light")) # You can use ?round, ?text and ?paste to read about these commands # for working with plots