Regression measure defined as $$ \frac{2}{n} \sum_{i=1}^n \frac{\left| t_i - r_i \right|}{\left| t_i \right| + \left| r_i \right|}. $$

Note

The score function calls mlr3measures::smape() from package mlr3measures.

If the measure is undefined for the input, NaN is returned. This can be customized by setting the field na_value.

Dictionary

This Measure can be instantiated via the dictionary mlr_measures or with the associated sugar function msr():

mlr_measures$get("smape")
msr("smape")

Meta Information

  • Type: "regr"

  • Range: \([0, 2]\)

  • Minimize: TRUE

  • Required prediction: response

See also