Standardized Residual
The standardized residual is the residual divided by its standard deviation.
Problem
Plot the standardized residual of the simple linear regression model of the data set faithful against the independent variable waiting.
Solution
We apply the lm function to a formula that describes the variable eruptions by the variable waiting, and save the linear regression model in a new variable eruption.lm. Then we compute the standardized residual with the rstandard function.
We now plot the standardized residual against the observed values of the variable waiting.
> plot(faithful$waiting, eruption.stdres,
+ ylab="Standardized Residuals",
+ xlab="Waiting Time",
+ main="Old Faithful Eruptions")
> abline(0, 0) # the horizon
+ ylab="Standardized Residuals",
+ xlab="Waiting Time",
+ main="Old Faithful Eruptions")
> abline(0, 0) # the horizon
Note
Further detail of the rstandard function can be found in the R documentation.
