evalAUC: Weighted AUC

In enmSdmX: Species Distribution Modeling and Ecological Niche Modeling

Weighted AUC

Description

This function calculates the area under the receiver-operator characteristic curve (AUC) following Mason & Graham (2002). Each case (presence/non-presence) can be assigned a weight, if desired.

Usage

evalAUC(
  pres,
  contrast,
  presWeight = rep(1, length(pres)),
  contrastWeight = rep(1, length(contrast)),
  na.rm = FALSE,
  ...
)

Arguments

pres	Vector of predictions for "positive" cases (e.g., predictions at presence sites).
contrast	Vector of predictions for "negative" cases (e.g., predictions at absence/background sites).
presWeight	Weights of positive cases. The default is to assign each positive case a weight of 1.
contrastWeight	Weights of contrast cases. The default is to assign each case a weight of 1.
na.rm	Logical. If TRUE then remove any positive cases and associated weights and contrast predictions and associated weights with NAs.
...	Other arguments (unused).

Value

A Numeric value.

References

Mason, S.J. and N.E. Graham. 2002. Areas beneath the relative operating characteristics (ROC) and relative operating levels (ROL) curves: Statistical significance and interpretation. Quarterly Journal of the Royal Meteorological Society 128:2145-2166. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1256/003590002320603584")}

See Also

pa_evaluate, evalMultiAUC

Examples

pres <- seq(0.5, 1, by=0.1)
contrast <- seq(0, 1, by=0.01)

# unweighted
evalAUC(pres, contrast)

# weighted (weight presences with low predictions more)
presWeight <- c(1, 1, 1, 0.5, 0.5, 0.5)
evalAUC(pres, contrast, presWeight=presWeight)

# weighted (weight presences with high predictions more)
presWeight <- c(0.5, 0.5, 0.5, 1, 1, 1)
evalAUC(pres, contrast, presWeight=presWeight)

# weight presences and absences
contrastWeight <- sqrt(contrast)
evalAUC(pres, contrast, presWeight=presWeight, contrastWeight=contrastWeight)

enmSdmX documentation built on April 3, 2025, 7:50 p.m.