compute.threshold.pooledROC.emp {AROC}

Pooled ROC-based threshold values.

Description

Estimates pooled ROC-based threshold values using the empirical estimator proposed by Hsieh and Turnbull (1996).

Usage

compute.threshold.pooledROC.emp(object, FPF = 0.5)

Arguments

object

An object of class AROC as produced by pooledROC.emp.

FPF

Numeric vector with the FPF at which to calculate the pooled ROC-based threshold values. Atomic values are also valid.

Value

As a result, the function provides a list with the following components:

thresholds

A vector with the estimated pooled ROC-based threshold values, one for each specified FPF.

FPF

the supplied FPF argument

TPF

TPFs corresponding to the estimated threshold.

References

Hsieh, F., and Turnbull, B.W. (1996). Nonparametric and semiparametric estimation of the receiver operating characteristic curve, The Annals of Statistics, 24, 25–40.

See Also

pooledROC.emp

Examples

library(AROC)
data(psa)
# Select the last measurement
newpsa <- psa[!duplicated(psa$id, fromLast = TRUE),]

# Log-transform the biomarker
newpsa$l_marker1 <- log(newpsa$marker1)


m0_emp <- pooledROC.emp(y0 = newpsa$l_marker1[newpsa$status == 0], 
            y1 = newpsa$l_marker1[newpsa$status == 1], p = seq(0,1,l=101), B = 500)

### Threshold values for a fixed FPF
th_m0_emp <- compute.threshold.pooledROC.emp(m0_emp, FPF = 0.1)

th_m0_emp$threshold