Hi everybody!
Using the iris dataset in R, I write a function to plot a confusion matrix.
library(e1071)
library(caTools)
library(caret)
iris$spl = sample.split(iris, SplitRatio = 0.1)
train <- subset(iris, iris$spl == TRUE)
test <- subset(iris, iris$spl == FALSE)
iris.nb <- naiveBayes(Species ~ ., data = train)
nb_train_predict <- predict(iris.nb, test[ , names(test) != "Species"])
cfm <- confusionMatrix(nb_train_predict, test$Species)
cfm
#ggplot confusion matrix
library(ggplot2)
library(scales)
ggplotConfusionMatrix <- function(m){
mytitle <- paste("Accuracy", percent_format()(m$overall[1]),
"Kappa", percent_format()(m$overall[2]))
p <-
ggplot(data = as.data.frame(m$table) ,
aes(x = Reference, y = Prediction)) +
geom_tile(aes(fill = log(Freq)), colour = "white") +
scale_fill_gradient(low = "white", high = "steelblue") +
geom_text(aes(x = Reference, y = Prediction, label = Freq)) +
theme(legend.position = "none") +
ggtitle(mytitle)
return(p)
}
ggplotConfusionMatrix(cfm)
My question is: How can I remove the "0" from the matrix? (I would like the gray squares without anything written)