| Description: | | A metaclassifier that selects a mid-point threshold on the probability output by a classifier. The midpoint threshold is set so that a given performance measure is optimized. Currently this is the F-measure by default. Performance is measured either on the training data, a hold-out set, or using cross-validation. In addition, the probabilities returned by the base learner can have their range expanded so that the output probabilities will reside between 0 and 1 (this is useful if the scheme normally produces probabilities in a very narrow range). |