fit<-rep(0,100)
> for(i in 900:1000){
+ dataNEW<-data[1:i,]
+ fit[i-899]
+ cop_model <- joeCopula(dim = 2)
+ fit <- fitCopula(cop_model, dataNEW, method = 'ml')
+ fi<- fitCopula(cop_model, dataNEW, method = 'ml')
+ coef(fi)
+ cop<-joeCopula(coef(fi),dim=2)
+ lambda(cop)
+ return(fit)
+ }

请问我这个关于COPULA函数求尾部相关系数的for循环哪里出