confusion.R

set.seed(0)
 actual = c('a','b','c')[runif(100, 1,4)] # actual labels
 predicted = actual # predicted labels
 predicted[runif(30,1,100)] = actual[runif(30,1,100)]  # introduce incorrect predictions
 cm = as.matrix(table(Actual = actual, Predicted = predicted)) # create the confusion matrix
 cm
##       Predicted
## Actual  a  b  c
##      a 24  2  1
##      b  3 30  4
##      c  0  5 31