Regression

Regression refers to a general class of statistical methods that relate a single response variable to one or more input (predictor) variables. This chapter first describes the simple linear regression model where one has a single predictor. R instructions for fitting the model, computing residuals, and graphing the fit and the residuals are included. Multiple regression using R is discussed where one has two or more input variables. Residual plots and plots of the predicted response and other relevant graphics are included. The chapter concludes by discussing examples of fitting a curve to model a non-linear relation between the response and predictor.