[R] Convert list with missing values to dataFrame

[MacQueen, Don]

Try,

sID <- c("a", "1,2,3", "b", "4,5,6")

tmp1 <- strsplit(sID,',')

tmp2 <- lapply(tmp1,
               function(x) if (length(x)==1) c('','',x) else x )

tmp3 <- matrix(unlist(tmp2),ncol=3, byrow=TRUE)


rID <- c("shr1125", "bwr331", "bwr330", "vjhr1022")

newdf <- data.frame(cbind(tmp3,rID))

You'll need to name the first three columns.

As an aside, note that you don't need the cbind in your
   data.frame(cbind(sID,rID))
because
   data.frame(sID,rID)
does just as well.
But cbind is needed in my example, because tmp3 is a matrix.

-Don


-- 
Don MacQueen

Lawrence Livermore National Laboratory
7000 East Ave., L-627
Livermore, CA 94550
925-423-1062





On 8/13/13 12:09 PM, "Steven Ranney" <steven.ranney at gmail.com> wrote:

>I have a dataFrame
>
>sID <- c("a", "1,2,3", "b", "4,5,6")
>rID <- c("shr1125", "bwr331", "bwr330", "vjhr1022")
>
>tmp <- data.frame(cbind(sID,rID))
>
>but I need to split tmp$sID into three different columns, filling
>locations
>where tmp$sID has only one value with NA.
>
>I can split tmp$sID by the comma
>
>tmp.1 <- strsplit(tmp$sID, ",")
>
>but I can't figure out how to convert the resulting list into a dataFrame.
>
>Ideally, tmp will become four columns wide, something like
>
>sID.a  sID.b  sID.c  rID
>NA     NA     a        shr1125
>1        2       3        bwr331
>NA     NA     b       bwr330
>4        5        6      vjhr1022
>
>Thoughts or suggestions?
>
>I tried
>
>havecomma - grep(',', tmp$sID)
>
>for( i in 1:nrow(tmp)){
>  if (!(tmp[i,] %in% havecomma)){
>    tmp$sID[i] <- paste(', ,', tmp$sID[i], sep="")
>    }
>    }
>
>and thought that I might be able to force the list into a dataframe once
>each component had three items, but it just seemed to apply the paste()
>function to everything which gave me a list with varying numbers of items.
>
>I'm stuck.
>
>Thanks for your help -
>
>SR
>
>
>
>
>
>
>Steven H. Ranney
>
>	[[alternative HTML version deleted]]
>
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