Regression measure defined as $$
\frac{1}{n} \sum_{i=1}^n w_i \frac{\left( t_i - r_i \right)}{\left| t_i \right|}.
$$
Good predictions score close to 0.
(numeric())
True (observed) values.
Must have the same length as response.
response
(numeric())
Predicted response values.
Must have the same length as truth.
sample_weights
(numeric())
Vector of non-negative and finite sample weights.
Must have the same length as truth.
The vector gets automatically normalized to sum to one.
Defaults to equal sample weights.
na_value
(numeric(1))
Value that should be returned if the measure is not defined for the input
(as described in the note). Default is NaN.