for(i in c(1:4,9:15,18,20:21,23))
{b[,i]=(b[,i]-min(b[,i]))/(max(b[,i])-min(b[,i]))}

for(i in c(5:8,16:17,19,22,24:25))
{b[,i]=(max(b[,i])-b[,i])/(max(b[,i])-min(b[,i]))}
b
for(i in 1:11){for(j in 1:25){
  if(b[i,j]==0){if(a[i,j]==max(a[,j])){b[i,j]=(a[i,j]-mean(a[,j])/sd(a[,j]))}
  else{b[i,j]=(mean(a[,j])-a[i,j])/sd(a[,j])}}
}}
请问熵值法首先对数据进行均值化处理，依然有负值，请问错在哪里？