8.7 Coding Activity:R Cheat Sheet

Suppose x and y are variables in dataframe d.

To fit an ols regression of Y on X:

mod <- lm(y ~ x, data = d)

To access coefficients from the model object:

mod$coefficients
or coef(mod)

To access fitted values from the model object:

mod$fitted
or fitted(mod)
or predict(mod)

To access residuals from the model object:

mod$residuals
or resid(mod)

To create a scatterplot that includes the regression line:

plot(d['x'], d['y'])
abline(mod)
or 
d %>% 
  ggplot() + 
  aes(x = x, y = y) + 
  geom_point() + 
  geom_smooth(method = lm)