olsrr: ols_step_forward_p – R documentation

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ols_step_forward_p

Stepwise forward regression

Description

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

Usage

ols_step_forward_p(model, ...)

## Default S3 method:
ols_step_forward_p(model, penter = 0.3,
  progress = FALSE, details = FALSE, ...)

## S3 method for class 'ols_step_forward_p'
plot(x, model = NA, print_plot = TRUE,
  ...)

Arguments

`model`	An object of class `lm`; the model should include all candidate predictor variables.
`...`	Other arguments.
`penter`	p value; variables with p value less than `penter` will enter into the model
`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_p`.
`print_plot`	logical; if `TRUE`, prints the plot else returns a plot object.

Value

ols_step_forward_p returns an object of class "ols_step_forward_p". An object of class "ols_step_forward_p" is a list containing the following components:

`model`	final model; an object of class `lm`
`steps`	number of steps
`predictors`	variables added to the model
`rsquare`	coefficient of determination
`aic`	akaike information criteria
`sbc`	bayesian information criteria
`sbic`	sawa's bayesian information criteria
`adjr`	adjusted r-square
`rmse`	root mean square error
`mallows_cp`	mallow's Cp
`indvar`	predictors

Deprecated Function

ols_step_forward() has been deprecated. Instead use ols_step_forward_p().

References

Chatterjee, Samprit and Hadi, Ali. Regression Analysis by Example. 5th ed. N.p.: John Wiley & Sons, 2012. Print.

Kutner, MH, Nachtscheim CJ, Neter J and Li W., 2004, Applied Linear Statistical Models (5th edition). Chicago, IL., McGraw Hill/Irwin.

Examples

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

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

# final model
k$model

olsrr

Tools for Building OLS Regression Models

v0.5.3

MIT + file LICENSE

Authors

Aravind Hebbali [aut, cre]

Initial release