olsrr (version 0.4.0)

ols_aic: AIC

Description

Akaike Information Criterion

Usage

ols_aic(model, method = c("R", "STATA", "SAS"))

Arguments

model

an object of class lm

method

a character vector; specify the method to compute AIC. Valid options include R, STATA and SAS

Value

Akaike Information Criterion

Details

AIC provides a means for model selection. Given a collection of models for the data, AIC estimates the quality of each model, relative to each of the other models. R and STATA use loglikelihood to compute AIC. SAS uses residual sum of squares. Below is the formula in each case:

R & STATA $$AIC = -2(loglikelihood) + 2p$$

SAS $$AIC = n * ln(SSE / n) + 2p$$

where n is the sample size and p is the number of model parameters including intercept.

References

Akaike, H. (1969). <U+201C>Fitting Autoregressive Models for Prediction.<U+201D> Annals of the Institute of Statistical Mathematics 21:243<U+2013>247.

Judge, G. G., Griffiths, W. E., Hill, R. C., and Lee, T.-C. (1980). The Theory and Practice of Econometrics. New York: John Wiley & Sons.

Examples

# NOT RUN {
# using R computation method
model <- lm(mpg ~ disp + hp + wt + qsec, data = mtcars)
ols_aic(model)

# using STATA computation method
model <- lm(mpg ~ disp + hp + wt + qsec, data = mtcars)
ols_aic(model, method = 'STATA')

# using SAS computation method
model <- lm(mpg ~ disp + hp + wt + qsec, data = mtcars)
ols_aic(model, method = 'SAS')
# }