新手刚学R语言遇到了一些问题，运行之后出现了这些报错，请问应该怎么解决？求大神指导，非常感谢！
> mulfa <- function(x){
+   n <- num_q[x]
+   A <- matrix(data=rep(0,nrow(data1)*n),nrow=nrow(data1),ncol=n)
+   
+   for(i in 1:nrow(data1)){
+     if(is.na(vv[i,x])){
+       A[i,] = rep(0,n)
+     }else{
+       vv[i,x] <- gsub("|","",vv[i,x],fixed=T)
+       a <- unlist(strsplit(vv[i,x],split=""))
+       a <- as.numeric(a)
+       for(j in 1:length(a)){
+         A[i,a[j]+1] <- 1
+       }
+     }
+   }
+   
+   name <- c()
+   B <- c("q500","q510","q520","q530","q540","q560","q580","q110")
+   for(m in 1:n){
+     name[m] <- paste(B[x],".",as.character(m))
+   }
+   colnames(A) <- name
+   return(as.data.frame(A))
+ }
> Q500 <- mulfa(1)
Error in `[<-`(`*tmp*`, i, a[j] + 1, value = 1) : subscript out of bounds

> Q510 <- mulfa(2)
Error in `[<-`(`*tmp*`, i, a[j] + 1, value = 1) : subscript out of bounds
> Q520 <- mulfa(3)
> Q530 <- mulfa(4)
Warning messages:
1: In mulfa(4) : NAs introduced by coercion
2: In mulfa(4) : NAs introduced by coercion