[R] Convert list with missing values to dataFrame

[arun]

Hi,

You could try:

tmp[,1]<- as.character(tmp[,1])
 tmp[,1][-grep(",",tmp[,1])]<-paste0(",,",tmp[,1][-grep(",",tmp[,1])])
tmp2<-data.frame(read.table(text=tmp[,1],sep=",",header=FALSE,stringsAsFactors=FALSE),rID=tmp[,2],stringsAsFactors=FALSE)
  colnames(tmp2)[1:3]<-paste("sID",letters[1:3],sep=".")
tmp2
#  sID.a sID.b sID.c      rID
#1    NA    NA     a  shr1125
#2     1     2     3   bwr331
#3    NA    NA     b   bwr330
#4     4     5     6 vjhr1022

BTW,
 data.frame(sID,rID,stringsAsFactors=FALSE)#cbind is not needed.  In this case, it is okay, 
#    sID      rID
#1     a  shr1125
#2 1,2,3   bwr331
#3     b   bwr330
#4 4,5,6 vjhr1022
#But if they were of different class:
str(data.frame(cbind(sID,Col2=1:4),stringsAsFactors=FALSE))
#'data.frame':    4 obs. of  2 variables:
# $ sID : chr  "a" "1,2,3" "b" "4,5,6"
# $ Col2: chr  "1" "2" "3" "4"
 str(data.frame(sID,Col2=1:4,stringsAsFactors=FALSE))
#'data.frame':    4 obs. of  2 variables:
# $ sID : chr  "a" "1,2,3" "b" "4,5,6"
# $ Col2: int  1 2 3 4



A.K.




----- Original Message -----
From: Steven Ranney <steven.ranney at gmail.com>
To: "r-help at r-project.org" <r-help at r-project.org>
Cc: 
Sent: Tuesday, August 13, 2013 3:09 PM
Subject: [R] Convert list with missing values to dataFrame

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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