如何在R中填写ROC图的AUC？

Question

我有这个ROC情节：

library(Epi)
library(pROC)
data(aSAH)
data <- aSAH
plot.roc(data$outcome, data$s100b)

我想为Area under the curve: 0.7314着色。

我试过......

x <- seq(1, 0, by = - .001)
polygon(x, roc(data$outcome, data$s100b), 
        col = rgb(.35,0.31,0.61, alpha = 0.4), 
        border = rgb(.35,0.31,0.61, 0.4),
        lwd=2)

...并收到错误消息：Error in xy.coords(x, y) : 'x' and 'y' lengths differ。

如何才能完成任务？

Answer 1

来自plot.roc的{​​{1}}功能已构建参数以启用（pROC）和调整（auc.polygon，auc.polygon.col等，请参阅{{1 }）AUC的显示。在您的情况下，您可以使用：

auc.polygon.border

Answer 2

尝试

library(Epi)
library(pROC)
data(aSAH)
data <- aSAH
res <- plot.roc(data$outcome, data$s100b)
polygon(with(res, cbind(specificities, sensitivities)), 
        col = rgb(.35,0.31,0.61, alpha = 0.4), 
        border = rgb(.35,0.31,0.61, 0.4),
        lwd=2)