在 r 中绘制一个显示百分比的混淆矩阵（ggplot）

Question

所以我有这两列，我想把它们变成一个混淆矩阵

faceEmotion
neutral
sad
happy
disgusted
angry
fearful
neutral
sad
sad
happy
happy
fearful

和

faceEmotionGuess
neutral
sad
happy
disgusted
angry
fearful
sad
disgusted
happy
happy
sad
neutral

我看到这个 beautiful confusion matrix 是用 ggplot 制作的，但我不知道他是如何制作的。 Google 帮助不大。

感谢您提供的任何帮助！

Answer 1

您的样本数据显然不如创建所需图像的样本数据丰富，但您可以像这样从数据中创建类似的图：

library(ggplot2)

tab <- table(df$faceEmotion, df$faceEmotionGuess)
tab <- tab / rowSums(tab)
tab <- as.data.frame(tab, stringsAsFactors = TRUE)
tab$Var2 <- factor(tab$Var2, rev(levels(tab$Var2)))

ggplot(tab, aes(Var1, Var2, fill = Freq)) +
  geom_tile() +
  geom_text(aes(label = scales::percent(Freq))) +
  scale_fill_gradient(low = "white", high = "#3575b5") +
  labs(x = "Emotion", y = "Guess", title = "Confusion matrix of emotions",
       fill = "Select") +
  theme(plot.title = element_text(size = 25, hjust = 0.5, 
                                  margin = margin(20, 0, 20, 0)),
        legend.title = element_text(size = 14, margin = margin(0, 20, 10, 0)),
        axis.title.x = element_text(margin = margin(20, 20, 20, 20), size = 18),
        axis.title.y = element_text(margin = margin(0, 20, 0, 10), size = 18))

数据

df <- structure(list(faceEmotion = structure(c(5L, 6L, 4L, 2L, 1L, 
3L, 5L, 6L, 6L, 4L, 4L, 3L), .Label = c("angry", "disgusted", 
"fearful", "happy", "neutral", "sad"), class = "factor"), 
faceEmotionGuess = structure(c(5L, 
6L, 4L, 2L, 1L, 3L, 6L, 2L, 4L, 4L, 6L, 5L), .Label = c("angry", 
"disgusted", "fearful", "happy", "neutral", "sad"), class = "factor")), 
class = "data.frame", row.names = c(NA, -12L))

df
#>    faceEmotion faceEmotionGuess
#> 1      neutral          neutral
#> 2          sad              sad
#> 3        happy            happy
#> 4    disgusted        disgusted
#> 5        angry            angry
#> 6      fearful          fearful
#> 7      neutral              sad
#> 8          sad        disgusted
#> 9          sad            happy
#> 10       happy            happy
#> 11       happy              sad
#> 12     fearful          neutral

^{由 reprex package (v0.3.0)}

于 2020-12-11 创建

在 r 中绘制一个显示百分比的混淆矩阵（ggplot）

Plot a confusion matrix in r showing percentages (ggplot)

r

ggplot2

confusion-matrix