R help - Aug 2011 - join columns

Dear R-help,

I wonder if you could give me some suggestions in how to do a union
join of two data frames as follow:
-> union join the common column, and insert a 0 if one is missing.

I made a function to perform the following, and I know it may not that
quite welly written, but it works.

Any suggestions are welcome, many thanks.

Anthony
> q1 = data.frame(a=1,b=2,c=3,row.names="q1")
     a b c
q1 1 2 3
> q2 = data.frame(d=4,b=1,a=4, row.names="q2")
     d b a
q2 4 1 4

->  myJoinColumns(q1,q2)
     a b c d
q1 1 2 3 0
q2 4 1 0 4


myJoinColumns <- function(q1,q2){
  allNames = sort(union(colnames(q1),colnames(q2)))
  for (i in 1:length(allNames)){
    t1 = which(colnames(q1) == allNames[i])
    t2 = which(colnames(q2) == allNames[i])

    if (length(t1) == 1){
      sec1 = q1[,t1]
    } else {
      sec1 = 0
    }

    if (length(t2) == 1){
      sec2 = q2[,t2]
    } else {
      sec2 = 0
    }

    if (i == 1){
      qTable = matrix(c(sec1,sec2))
    }else{
      qTable = cbind(qTable,c(sec1,sec2))
    }
  }
  colnames(qTable) = allNames
  rownames(qTable) = c("q1","q2")
  qTable
}

On Aug 10, 2011, at 11:04 AM, Anthony Ching Ho Ng wrote:
> Dear R-help,
>
> I wonder if you could give me some suggestions in how to do a union
> join of two data frames as follow:
> -> union join the common column, and insert a 0 if one is missing.
>
> I made a function to perform the following, and I know it may not that
> quite welly written, but it works.
>
> Any suggestions are welcome, many thanks.
>
> Anthony
>
>> q1 = data.frame(a=1,b=2,c=3,row.names="q1")
>     a b c
> q1 1 2 3
>
>> q2 = data.frame(d=4,b=1,a=4, row.names="q2")
>     d b a
> q2 4 1 4
>
> ->  myJoinColumns(q1,q2)
>     a b c d
> q1 1 2 3 0
> q2 4 1 0 4
 > temp <- merge(q1,q2, all=TRUE)
 > temp[is.na(temp)] <- 0
 > temp
   a b c d
1 1 2 3 0
2 4 1 0 4
>
>
> myJoinColumns <- function(q1,q2){
>  allNames = sort(union(colnames(q1),colnames(q2)))
>  for (i in 1:length(allNames)){
>    t1 = which(colnames(q1) == allNames[i])
>    t2 = which(colnames(q2) == allNames[i])
>
>    if (length(t1) == 1){
>      sec1 = q1[,t1]
>    } else {
>      sec1 = 0
>    }
>
>    if (length(t2) == 1){
>      sec2 = q2[,t2]
>    } else {
>      sec2 = 0
>    }
>
>    if (i == 1){
>      qTable = matrix(c(sec1,sec2))
>    }else{
>      qTable = cbind(qTable,c(sec1,sec2))
>    }
>  }
>  colnames(qTable) = allNames
>  rownames(qTable) = c("q1","q2")
>  qTable
> }
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
West Hartford, CT

Try this:

merge(q1, q2, all = TRUE)

On Wed, Aug 10, 2011 at 12:04 PM, Anthony Ching Ho Ng
<anthony.ch.ng at gmail.com> wrote:
> Dear R-help,
>
> I wonder if you could give me some suggestions in how to do a union
> join of two data frames as follow:
> -> union join the common column, and insert a 0 if one is missing.
>
> I made a function to perform the following, and I know it may not that
> quite welly written, but it works.
>
> Any suggestions are welcome, many thanks.
>
> Anthony
>
>> q1 = data.frame(a=1,b=2,c=3,row.names="q1")
> ? ? a b c
> q1 1 2 3
>
>> q2 = data.frame(d=4,b=1,a=4, row.names="q2")
> ? ? d b a
> q2 4 1 4
>
> -> ?myJoinColumns(q1,q2)
> ? ? a b c d
> q1 1 2 3 0
> q2 4 1 0 4
>
>
> myJoinColumns <- function(q1,q2){
> ?allNames = sort(union(colnames(q1),colnames(q2)))
> ?for (i in 1:length(allNames)){
> ? ?t1 = which(colnames(q1) == allNames[i])
> ? ?t2 = which(colnames(q2) == allNames[i])
>
> ? ?if (length(t1) == 1){
> ? ? ?sec1 = q1[,t1]
> ? ?} else {
> ? ? ?sec1 = 0
> ? ?}
>
> ? ?if (length(t2) == 1){
> ? ? ?sec2 = q2[,t2]
> ? ?} else {
> ? ? ?sec2 = 0
> ? ?}
>
> ? ?if (i == 1){
> ? ? ?qTable = matrix(c(sec1,sec2))
> ? ?}else{
> ? ? ?qTable = cbind(qTable,c(sec1,sec2))
> ? ?}
> ?}
> ?colnames(qTable) = allNames
> ?rownames(qTable) = c("q1","q2")
> ?qTable
> }
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Henrique Dallazuanna
Curitiba-Paran?-Brasil
25? 25' 40" S 49? 16' 22" O