Apply Threshold

Synopsis

This operator applies a threshold on soft classified data.

Description

The Apply Threshold operator applies the given threshold to a labeled ExampleSet and maps a soft prediction to crisp values. The threshold is provided through thethresholdport. Mostly the Create Threshold operator is used for creating thresholds before it is applied using the Apply Threshold operator. If the confidence for the second class is greater than the given threshold the prediction is set to this class otherwise it is set to the other class. This can be easily understood by studying the attached Example Process.

Among various classification methods, there are two main groups of methods: soft and hard classification. In particular, a soft classification rule generally estimates the class conditional probabilities explicitly and then makes the class prediction based on the largest estimated probability. In contrast, hard classification bypasses the requirement of class probability estimation and directly estimates the classification boundary.

Input

example set

This input port expects a labeled ExampleSet. The ExampleSet should havelabelandpredictionattributes as well as attributes for confidence of predictions.

threshold

The threshold is provided through this input port. Frequently, the Create Threshold operator is used for providing threshold at this port.

Output

example set

The predictions of the input ExampleSet are changed according to the threshold given at thethresholdport and the modified ExampleSet is delivered through this port.