adjust_Rsq: Adjust a regression model R-squared for overfitting
Description
Estimate shrinkage for regression models
Usage
adjust_Rsq(Rsq, n, p, adjust = c("fisher", "pop", "cv"))
Value
An adjusted R-squared value.
Arguments
Rsq
Observed model R-squared
n
Sample size
p
Number of predictors
adjust
Which adjustment to apply. Options are "fisher" for the Adjusted R-squared method used in stats::lm(), "pop" for the positive-part Pratt estimator of the population R-squared, and "cv" for the Browne/positive-part Pratt estimator of the cross-validity R-squared. Based on Shieh (2008), these are the estimators for the population and cross-validity R-squared values that show the least bias with a minimal increase in computational complexity.
References
Shieh, G. (2008).
Improved shrinkage estimation of squared multiple correlation coefficient and squared cross-validity coefficient.
Organizational Research Methods, 11(2), 387–407. tools:::Rd_expr_doi("10.1177/1094428106292901")