有这么一段代码，出现了错误
for(i in n.Portfolio){
  Portfolio.i <- Portfolio[Portfolio$stkcd == i,]
  n.dayi <- dim(Portfolio.i)[1]
  day <- c(1: n.dayi)
  Portfolio.i <- cbind(Portfolio.i, day)
  Begin.i <- factor(Portfolio.i[(Portfolio.i$date == Portfolio.i$infopubdt), 11])
  End.i <- Begin.i + 60
    ifelse(End.i > n.dayi, a <- a + 1,
           (ifelse(i == 1000004, Port <- (Portfolio.i[(Begin.i : End.i), ]),
                   Port <- rbind(Port, (Portfolio.i[(Begin.i : End.i), ])))))
}
Warning messages:
1: In Begin.i:End.i :
  numerical expression has 4 elements: only the first used