程序如下:
Pettitt_change<-function(mydat,ut,chg_point,coef){
{n=length(mydat)
s=0
ut=numeric(n-1)
for (i in1:n-1)
for (j ini+1:n)
s=s+sign(mydat[j]-mydat)
ut=s
}
kmax=max(abs(ut))
chg_point=find(abs(ut)==kmax)
coef=2*exp(-6*kmax^2/(n^3+n^2))
}
Pettitt_change(mydat)
Error in ut = s : replacement has lengthzero
出现这个错误是怎么回事呢?谢谢!