Forecasts are in the range [-50, +50] (theoretically any real number, but Vowpal Wabbit truncates it to [-50, +50]).
To convert them to {-1, +1}, use --binary . Positive forecasts are simply displayed at +1, minus -1.
To convert them to [0, +1], use --link=logistic . This uses the boolean function 1 / (1 + exp (-x)). You should also use --loss_function=logistic if you want to interpret numbers as probabilities.
To convert them to [-1, +1], use --link=glf1 . This uses the formula 2 / (1 + exp (-x)) - 1 (generalized logistic function with limits 1).
Martin popel
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