protected Tensor delta = tf.Variable(1.0);

public Huber(

string reduction = null,

Tensor delta = null,

string name = null) :

base(reduction: reduction, name: name == null ? "huber" : name)

{

this.delta = delta == null ? this.delta : delta;

}

public override Tensor Apply(Tensor y_true = null, Tensor y_pred = null, bool from_logits = false, int axis = -1)

{

Tensor y_pred_cast = math_ops.cast(y_pred, dtype: TF_DataType.TF_FLOAT);

Tensor y_true_cast = math_ops.cast(y_true, dtype: TF_DataType.TF_FLOAT);

Tensor delta = math_ops.cast(this.delta, dtype: TF_DataType.TF_FLOAT);

Tensor error = math_ops.subtract(y_pred_cast, y_true_cast);

Tensor abs_error = math_ops.abs(error);

Tensor half = ops.convert_to_tensor(0.5, dtype: abs_error.dtype);

return gen_math_ops.mean(array_ops.where_v2(abs_error <= delta,

half * math_ops.pow(error, 2),

half * math_ops.pow(delta, 2) + delta * (abs_error - delta)),

ops.convert_to_tensor(-1));

}