Plot confusion matrix in R using ggplot

A slightly more modular solution based on MYaseen208's answer. Might be more effective for large datasets / multinomial classification:

confusion_matrix <- as.data.frame(table(predicted_class, actual_class))

ggplot(data = confusion_matrix
       mapping = aes(x = Var1,
                     y = Var2)) +
  geom_tile(aes(fill = Freq)) +
  geom_text(aes(label = sprintf("%1.0f", Freq)), vjust = 1) +
  scale_fill_gradient(low = "blue",
                      high = "red",
                      trans = "log") # if your results aren't quite as clear as the above example

This could be a good start

library(ggplot2)
ggplot(data =  dframe, mapping = aes(x = label, y = method)) +
  geom_tile(aes(fill = value), colour = "white") +
  geom_text(aes(label = sprintf("%1.0f",value)), vjust = 1) +
  scale_fill_gradient(low = "white", high = "steelblue")

Edited

TClass <- factor(c(0, 0, 1, 1))
PClass <- factor(c(0, 1, 0, 1))
Y      <- c(2816, 248, 34, 235)
df <- data.frame(TClass, PClass, Y)

library(ggplot2)
ggplot(data =  df, mapping = aes(x = TClass, y = PClass)) +
  geom_tile(aes(fill = Y), colour = "white") +
  geom_text(aes(label = sprintf("%1.0f", Y)), vjust = 1) +
  scale_fill_gradient(low = "blue", high = "red") +
  theme_bw() + theme(legend.position = "none")