olsrr (version 0.6.0)

ols_step_forward_aic: Stepwise AIC forward regression

Description

Build regression model from a set of candidate predictor variables by entering predictors based on akaike information criterion, in a stepwise manner until there is no variable left to enter any more.

Usage

ols_step_forward_aic(model, ...)
# S3 method for default
ols_step_forward_aic(
  model,
  include = NULL,
  exclude = NULL,
  progress = FALSE,
  details = FALSE,
  ...
)
# S3 method for ols_step_forward_aic
plot(x, print_plot = TRUE, details = TRUE, digits = 3, ...)

Value

List containing the following components:

model

final model; an object of class lm

metrics

selection metrics

others

list; info used for plotting and printing

Arguments

model

An object of class lm.

...

Other arguments.

include

Character or numeric vector; variables to be included in selection process.

exclude

Character or numeric vector; variables to be excluded from selection process.

progress

Logical; if TRUE, will display variable selection progress.

details

Logical; if TRUE, will print the regression result at each step.

x

An object of class ols_step_forward_*.

print_plot

logical; if TRUE, prints the plot else returns a plot object.

digits

Number of decimal places to display.

References

Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer.

See Also

Other forward selection procedures: ols_step_forward_adj_r2(), ols_step_forward_p(), ols_step_forward_r2(), ols_step_forward_sbc(), ols_step_forward_sbic()

Examples

# stepwise forward regression
model <- lm(y ~ ., data = surgical)
ols_step_forward_aic(model)

# stepwise forward regression plot
k <- ols_step_forward_aic(model)
plot(k)

# selection metrics
k$metrics

# extract final model
k$model

# include or exclude variables
# force variable to be included in selection process
ols_step_forward_aic(model, include = c("age"))

# use index of variable instead of name
ols_step_forward_aic(model, include = c(5))

# force variable to be excluded from selection process
ols_step_forward_aic(model, exclude = c("liver_test"))

# use index of variable instead of name
ols_step_forward_aic(model, exclude = c(4))

# include & exclude variables in the selection process
ols_step_forward_aic(model, include = c("age"), exclude = c("liver_test"))

# use index of variable instead of name
ols_step_forward_aic(model, include = c(5), exclude = c(4))