read.table("D:/Program Files/R/R/R-2.15.2/bin/i386/test.csv",header=T,sep=",")->mydata
mydata->A          #A是一个矩阵
Ex=function(x){
mean(x)
}
En0=function(x){
x1=x-Ex              #这里做减法的时候，由于Ex定义成了一个函数，而我要计算的是x减去EX的值   ，怎么办？？？
(1/sqrt(2*pi))*(1/n)*sum(abs(x1))
}
He0=function(x){
var(x)
sqrt(abs(var-En0^2))
}
Ex=function(x){
mean(x[x!=0],na.rm=T)
}
En=function(x){
En0(x[x!=0],na.rm=T)
}
He=function(x){
He0(x[x!=0],na.rm=T)
}
apply(A,2,Ex)
apply(A,2,En)
apply(A,2,He)