Simplified return value

Author: leeper

R/mergeNA.r

@@ -5,9 +5,9 @@ mergeNA <- function(...) {
 lengths <- sapply(vars,FUN=length)
 # check variable lengths
 if(!identical(rep(lengths[1],length(vars)), lengths))
-stop("Vectors specified in '...' have different lengths")
+stop("Vectors specified have different lengths")
 # test for NAs in each vector
-a <- do.call(cbind,a)
+a <- do.call(cbind,vars)
 amat <- is.na(a)
 # check for mutual missigness
 mutual <- rowSums(!amat) > 1 #mutual <- apply(!amat, 1, sum) > 1
@@ -21,10 +21,7 @@ mergeNA <- function(...) {
 notNA <- lapply(seq_len(ncol(notNA)), function(i) notNA[,i])
 # pairs of NA positions and mergeable values
 p <- mapply(function(val,pos) val[pos], vars, notNA, SIMPLIFY=FALSE)
-pairs <- cbind(unlist(notNA),unlist(p))
-# start with first variable
-out <- vars[[1]]
-# replace NAs, if applicable with values from `pairs`
-out[pairs[,1]] <- pairs[,2]
-return(out)
+# replace NAs, if applicable
+vars[[1]][unlist(notNA)] <- unlist(p)
+return(vars[[1]])
 }