Get the the maximum tolerated squared Pearson correlation coefficient r2 (with 0 ≤ r2 ≤ 1) between the prediction error on verification data and the actual target values. Setting an rSquared threshold is just a hint for the regression algorithm. It cannot be guaranteed that the constructed model really has an rSquared value below that threshold. Note: r2=0 means that the prediction error and the target field values are uncorrelated, r2=1 means that the two values are perfectly (positively or negatively) correlated. Therefore, setting an upper threshold for r2 means setting an upper limit for the acceptable systematic error of the model.
The return Value is of type DOUBLE