用R语言计算信息熵

test.entropy <- function(d){

print(d)
res <- 0
for(i in 1:length(d))
{
  if(d[i]!=0)
        res <- res + d[i]*log(d[i])
    }
return (-res)
}

d1=c(0.25,0.25,0.25,0.25)
d2=c(0.5,0.5,0,0)
d3=c(0.8,0.2,0,0)

d4=c(1,0,0,0)

print(test.entropy(d=d1))
print(test.entropy(d=d2))
print(test.entropy(d=d3))
print(test.entropy(d=d4))

结果：

print(test.entropy(d=d1))[1] 0.25 0.25 0.25 0.25[1] 1.386294> > > print(test.entropy(d=d2))[1] 0.5 0.5 0.0 0.0[1] 0.6931472> > print(test.entropy(d=d3))[1] 0.8 0.2 0.0 0.0[1] 0.5004024> > print(test.entropy(d=d4))[1] 1 0 0 0[1] 0