cvq2.setA: Small data set to demonstrate the difference between the conventional squared correlation coefficient and the predictive squared correlation coefficient while performing a Leave-One-Out cross validation.
Description
Contains a small data set with four observations, the observed value y depends on two parameters ($x_1$, $x_2$).
If a cross validation is applied to the data set, the resulting $q^2_{cv}$ value is much smaller than the $r^2$ value.