public static KerasSymbol CategorialHinge(KerasSymbol y_true, KerasSymbol y_pred)
{
var pos = K.Sum(y_true * y_pred, axis: -1);
var neg = K.Max((1 - y_true) * y_pred, axis: -1);
return(K.Maximum(0, neg - pos + 1));
}
public static KerasSymbol Softmax(KerasSymbol x, int axis = -1)
{
var ndim = K.NDim(x);
if (ndim == 2)
{
return(K.Softmax(x));
}
else if (ndim > 2)
{
var e = K.Exp(x - K.Max(x, axis: axis, keepdims: true));
var s = K.Sum(e, axis: axis, keepdims: true);
return(e / s);
}
else if (ndim == 0)
{
// x dim is not inferred yet
return(K.Softmax(x));
}
else
{
throw new Exception($"Cannot apply softmax to a tensor that is 1D. Received input: {x}");
}
}
public static KerasSymbol MultiHotSparseCategoricalAccuracy(KerasSymbol y_true, KerasSymbol y_pred)
{
return(K.Cast(K.Equal(K.Max(y_true, axis: -1), K.Cast(K.Argmax(y_pred, axis: -1), K.FloatX())), K.FloatX()));
}