Measure to compare true observed response with predicted response in regression tasks.
Usage
rsq(truth, response, na_value = NaN, ...)
Value
Performance value as numeric(1).
Arguments
truth
(numeric())
True (observed) values.
Must have the same length as response.
response
(numeric())
Predicted response values.
Must have the same length as truth.
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.
...
(any)
Additional arguments. Currently ignored.
Meta Information
Type: "regr"
Range: \((-\infty, 1]\)
Minimize: FALSE
Required prediction: response
Details
R Squared is defined as $$
1 - \frac{\sum_{i=1}^n \left( t_i - r_i \right)^2}{\sum_{i=1}^n \left( t_i - \bar{t} \right)^2},
$$
where \(\bar{t} = \sum_{i=1}^n t_i\).
Also known as coefficient of determination or explained variation.
Subtracts the rse() from 1, hence it compares the squared error of
the predictions relative to a naive model predicting the mean.