I have fit a linear model using the
lm function in R...
model <- lm(trans.baseline.CD4 ~ hiv$Julian.Date)
... and I would like to assess the quality of the model's fit. Is there a function in R that will do this? Alternatively, I found a formula for goodness-of-fit involving the sum of squared residuals given the null and alternative hypotheses, but I don't know how to get these values either. Any pointers?