ggplot2 (version 0.9.0)

fortify.lm: Supplement the data fitted to a linear model with model fit statistics.

Description

If you have missing values in your model data, you may need to refit the model with na.action = na.exclude.

Usage

## S3 method for class 'lm':
fortify(model, data = model$model, ...)

Arguments

model

linear model

data

data set, defaults to data used to fit model

...

not used by this method

Value

• The original data with extra columns:
• .hat
  Diagonal of the hat matrix
• .sigma
  Estimate of residual standard deviation when corresponding observation is dropped from model
• .cooksd
  Cooks distance, cooks.distance
• .fitted
  Fitted values of model
• .resid
  Residuals
• .stdresid
  Standardised residuals

Examples

mod <- lm(mpg ~ wt, data = mtcars)
head(fortify(mod))
head(fortify(mod, mtcars))

plot(mod, which = 1)
qplot(.fitted, .resid, data = mod) +
  geom_hline(yintercept = 0) +
  geom_smooth(se = FALSE)
qplot(.fitted, .stdresid, data = mod) +
  geom_hline(yintercept = 0) +
  geom_smooth(se = FALSE)
qplot(.fitted, .stdresid, data = fortify(mod, mtcars),
  colour = factor(cyl))
qplot(mpg, .stdresid, data = fortify(mod, mtcars), colour = factor(cyl))

plot(mod, which = 2)
# qplot(sample =.stdresid, data = mod, stat = "qq") + geom_abline()

plot(mod, which = 3)
qplot(.fitted, sqrt(abs(.stdresid)), data = mod) + geom_smooth(se = FALSE)

plot(mod, which = 4)
qplot(seq_along(.cooksd), .cooksd, data = mod, geom = "bar",
 stat="identity")

plot(mod, which = 5)
qplot(.hat, .stdresid, data = mod) + geom_smooth(se = FALSE)
ggplot(mod, aes(.hat, .stdresid)) +
  geom_vline(size = 2, colour = "white", xintercept = 0) +
  geom_hline(size = 2, colour = "white", yintercept = 0) +
  geom_point() + geom_smooth(se = FALSE)

qplot(.hat, .stdresid, data = mod, size = .cooksd) +
  geom_smooth(se = FALSE, size = 0.5)

plot(mod, which = 6)
ggplot(mod, aes(.hat, .cooksd)) +
  geom_vline(xintercept = 0, colour = NA) +
  geom_abline(slope = seq(0, 3, by = 0.5), colour = "white") +
  geom_smooth(se = FALSE) +
  geom_point()
qplot(.hat, .cooksd, size = .cooksd / .hat, data = mod) + scale_area()