R/residplot.R

In trinker/Regression: Fuctions for linear models

residplot <- function(fit, nbreaks=10) {
               z <- rstudent(fit)
               hist(z, breaks=nbreaks, freq=FALSE, 
      xlab="Studentized Residual", 
      main="Distribution of Errors")
               rug(jitter(z), col="brown")
               curve(dnorm(x, mean=mean(z), sd=sd(z)), 
                     add=TRUE, col="blue", lwd=2)
               lines(density(z)$x, density(z)$y, 
                     col="red", lwd=2, lty=2)
               legend("topright", 
                     legend = c( "Normal Curve", "Kernel Density Curve"), 
                     lty=1:2, col=c("blue","red"), cex=.7)
          }