R语言实现softmax

softmax <- function(a){
  max_a <- max(a)
  a <- a-max_a
  exp_a <- exp(a)
  sum_exp_a <- sum(exp_a)
  y <- exp_a/sum_exp_a
  return(y)
}
a <- c(1010,1000,990)
y <- softmax(a)
y