ova_accuracy - one-vs-all multiclass accuracy

rlscore.measure.ova_accuracy(Y, P)

One-vs-all classification accuracy for multi-class problems.

Computes the accuracy for a one-versus-all decomposed classification problem. Each column in Y and P correspond to one possible class label. On each row, exactly one column in Y is 1, all the rest must be -1. The prediction for the i:th example is computed by taking the argmax over the indices of row i in P.

Parameters:

Y : {array-like}, shape = [n_samples] or [n_samples, n_classes]

Correct labels, must belong to set {-1,1}, with exactly one 1 on each row.

P : {array-like}, shape = [n_samples] or [n_samples, n_classes]

Predicted labels, can be any real numbers.

Returns:

accuracy : float

number between 0 and 1