使用的是pROC包，關(guān)于roc（）的參數(shù)我有點(diǎn)疑惑，modelroc <- roc(my第一個(gè)mydata.testy是實(shí)際數(shù)據(jù)里y變量的值，res_cost是我使用C50包構(gòu)建決策樹之后用predict.C5.0函數(shù)得到的預(yù)測結(jié)果，這兩個(gè)都是factor的vector應(yīng)該是，然后直接運(yùn)行的話報(bào)錯(cuò)：第二個(gè)參數(shù)必須是numeric或者有序的，我就用as.numeric把res_cost轉(zhuǎn)換成數(shù)字最后得到的圖像是一條直線沒有折點(diǎn)，如何設(shè)置更多的折點(diǎn)？

tree <- rpart(HCAI ~ hospital + age + gender + admseason + low_protein + UC + UN + UCN + UCL + UNL + LOS + fever + LOSICU + surnum + preoperative + postoperative + postoperative_ant + postoperative_antD + bacterial_culture + antibiotic + antibioticD + comb_ant + comb_antD + spec_ant + spec_antD??+ sing_antD + doub_antD + Trip_antD + blood_exam + abblood + uri_exam + aburi + ventilatorD + ventilatorT + cvcD + cvcT + uriD + uriT + add, method = "class", data = LR_train)
tree

#ROC曲線的繪制
library(pROC)
froc <- roc(LR_trainHCAI，treey)
HCAI,treey)
froc
plot(froc, print.auc = TRUE, auc.polygon = TRUE, legacy.axes = TRUE,
? ???grid = c(0.1, 0.2), grid.col = c("green", "red"), max.auc.polygon = TRUE,??
? ???auc.polygon.col = "skyblue", xlab = "1-specificity", ylab = "sensitivity")
ci(froc)