Compute AUCs using the trapezoid method

Compute AUCs using the trapezoid method

Usage

trapezoid_auc(xs, ys)

partial_trapezoid_auc(xs, ys, xlim)

Arguments

xs, ys

x and y positions

xlim

two-element vector (a range) of the xs to sum over

Value

the area under the curve computed using the trapezoid method. For partial_trapezoid_auc(), the partial area under the curve is computed.

Examples

if (requireNamespace("rstanarm", quietly = TRUE)) {
  wells <- rstanarm::wells
  r <- pROC::roc(switch ~ arsenic, wells)
  pROC::auc(r)
  trapezoid_auc(r$specificities, r$sensitivities)

  pROC::auc(r, partial.auc = c(.9, 1), partial.auc.focus = "sp")
  partial_trapezoid_auc(r$specificities, r$sensitivities, c(.9, 1))

  pROC::auc(r, partial.auc = c(.9, 1), partial.auc.focus = "se")
  partial_trapezoid_auc(r$sensitivities, r$specificities, c(.9, 1))

  pROC::auc(r, partial.auc = c(.1, .9), partial.auc.focus = "sp")
  partial_trapezoid_auc(r$specificities, r$sensitivities, c(.1, .9))

  pROC::auc(r, partial.auc = c(.1, .9), partial.auc.focus = "se")
  partial_trapezoid_auc(r$sensitivities, r$specificities, c(.1, .9))
}
#> Setting levels: control = 0, case = 1
#> Setting direction: controls < cases
#> [1] 0.5086048