Measure to compare true observed response with predicted response in regression tasks.
Note that this is an unaggregated measure, returning the losses per observation.
Usage
linex(truth, response, a = -1, b = 1, ...)
Value
Performance value as numeric(length(truth)).
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.
a
(numeric(1))
Shape parameter controlling asymmetry.
Negative values penalize overestimation more, positive values penalize underestimation more.
As a approaches 0, the loss resembles squared error loss. Default is -1.
b
(numeric(1))
Positive scaling factor for the loss. Larger values increase the loss magnitude.
Default is 1.
...
(any)
Additional arguments. Currently ignored.
Meta Information
Type: "regr"
Range (per observation): \([0, \infty)\)
Minimize (per observation): TRUE
Required prediction: response
Details
The Linear-Exponential Loss is defined as $$
b (\exp (t_i - r_i) - a (t_i - r_i) - 1),
$$
where \(a \neq 0, b > 0\).
References
Varian, R. H (1975).
“A Bayesian Approach to Real Estate Assessment.”
In Fienberg SE, Zellner A (eds.), Studies in Bayesian Econometrics and Statistics: In Honor of Leonard J. Savage, 195--208.
North-Holland, Amsterdam.