使用geom_rect()在混淆矩阵中绘制矩形

library(ggplot2)

# 创建一个示例混淆矩阵
confusion_matrix <- matrix(c(50, 10, 5, 35), nrow = 2, byrow = TRUE)
colnames(confusion_matrix) <- c("Predicted_0", "Predicted_1")
rownames(confusion_matrix) <- c("Actual_0", "Actual_1")

# 将混淆矩阵转换为数据框
confusion_df <- as.data.frame.table(confusion_matrix)

# 创建一个空白的ggplot对象
p <- ggplot() +

  # 添加矩形
  geom_rect(data = confusion_df, aes(xmin = Var2 - 0.5, xmax = Var2 + 0.5, ymin = Var1 - 0.5, ymax = Var1 + 0.5, fill = Freq), color = "black") +

  # 添加文本标签
  geom_text(data = confusion_df, aes(x = Var2, y = Var1, label = Freq), color = "white", size = 12) +

  # 设置坐标轴标签和标题
  labs(x = "Predicted", y = "Actual", title = "Confusion Matrix")

# 显示图形
print(p)