R confusionMatrix()

1 개요

R confusionMatrix()

• 혼동행렬을 만드는 R 함수

2 전체 정보 조회

library(caret) # confusionMatrix()
t <- as.table(rbind(c(231, 32), c(27, 54)))
dimnames(t) <- list(pred = c("abnormal", "normal"), truth = c("abnormal", "normal"))
confusionMatrix(t)

library(caret) # confusionMatrix()
lvs <- c("normal", "abnormal")
truth <- factor(rep(lvs, times = c(86, 258)), levels = rev(lvs))
pred <- factor(
  c(rep(lvs, times = c(54, 32)), rep(lvs, times = c(27, 231))),               
  levels = rev(lvs))
confusionMatrix(pred, truth)

library(caret) # confusionMatrix()
lvs <- c("normal", "abnormal")
truth <- factor(rep(lvs, times = c(86, 258)), levels = rev(lvs))
pred <- factor(
  c(rep(lvs, times = c(54, 32)), rep(lvs, times = c(27, 231))),               
  levels = rev(lvs))
xtab <- table(pred, truth)
confusionMatrix(xtab)

3 특정값만 추출 ★

library(caret) # confusionMatrix()
t <- as.table(rbind(c(231, 32), c(27, 54)))
dimnames(t) <- list(pred = c("abnormal", "normal"), truth = c("abnormal", "normal"))
cm <- confusionMatrix(t)
cm$overall["Accuracy"]
cm$byClass["Sensitivity"]
cm$byClass["Specificity"]
cm$byClass["Specificity"]
cm$byClass["Precision"]
cm$byClass["Recall"]

4 같이 보기

• 혼동행렬
• R sensitivity()
• R specificity()
• R posPredValue()
• R negPredValue()

5 참고

• https://www.rdocumentation.org/packages/caret/versions/6.0-86/topics/confusionMatrix