我“更新”了插入符号中的twoClassSummary 函数，以使用插入符号函数包含阴性和阳性预测值：
testfun <- function (data, lev = NULL, model = NULL)
{
lvls <- levels(data$obs)
if (length(lvls) > 2)
stop(paste("Your outcome has", length(lvls), "levels. The
twoClassSummary() function isn't appropriate."))
requireNamespaceQuietStop("ModelMetrics")
if (!all(levels(data[, "pred"]) == lvls))
stop("levels of observed and predicted data do not match")
data$y = as.numeric(data$obs == lvls[2])
rocAUC <- ModelMetrics::auc(ifelse(data$obs == lev[2], 0,
1), data[, lvls[1]])
out <- c(rocAUC, sensitivity(data[, "pred"], data[, "obs"], lev[1]),
specificity(data[, "pred"], data[, "obs"], lev[2]),
# next 3 lines are my additions and …