R help - Jun 2009 - Matching data to a new column

Hi all,

I wonder if anyone can help,

I have a dataframe with columns for...

'I.D'  'age'  'mothers I.D'
01     5       03
02     6       06
03     16     NA
04     8       06
05     3       NA
06     17     NA

I need to create a new column for 'mothers age' which puts the age of
the individual with 'mothers i.d' into the row for her offspring (so
individual 01 would have 16 in the mothers age column, as thats the age of
individual 03)

Hope that makes sense, any help appreciated,

Thanks
Laura

	[[alternative HTML version deleted]]

Kubasiewicz, Laura <laura.kubasiewicz08 <at> imperial.ac.uk> writes:
> I have a dataframe with columns for...
> 
> 'I.D'  'age'  'mothers I.D'
> 01     5       03
> 02     6       06
> 03     16     NA
> 04     8       06
> 05     3       NA
> 06     17     NA
> 
> I need to create a new column for 'mothers age' which puts the age
of the
individual with 'mothers i.d' into
> the row for her offspring (so individual 01 would have 16 in the mothers
age
column, as thats the age of
> individual 03)
> 
That's at typical join in SQL language, and it is handled in R with function
merge. In your special case, you would merge the dataframe with itself, 
so something like

merge(fr,fr, by... and check the NA cases)

Dieter

x <- "I.D  age  'MID'
01     5       03
02     6       06
03     16     NA
04     8       06
05     3       NA
06     17     NA"
    
xx <- read.table(textConnection(x), header=TRUE); xx
closeAllConnections()

ag1 <- xx[, c(1,2)] ; ag1
ag2 <- xx[, c(1,3)] ; ag2
names(ag2[2]) <- "I.D"

merge(ag1,ag2, by="I.D")


--- On Fri, 6/26/09, Kubasiewicz, Laura <laura.kubasiewicz08 at
imperial.ac.uk> wrote:
> From: Kubasiewicz, Laura <laura.kubasiewicz08 at imperial.ac.uk>
> Subject: [R] Matching data to a new column
> To: "r-help at r-project.org" <r-help at r-project.org>
> Received: Friday, June 26, 2009, 6:55 AM
> 
> Hi all,
> 
> I wonder if anyone can help,
> 
> I have a dataframe with columns for...
> 
> 'I.D'? 'age'? 'mothers I.D'
> 01? ???5? ?
> ???03
> 02? ???6? ?
> ???06
> 03? ???16? ???NA
> 04? ???8? ?
> ???06
> 05? ???3? ?
> ???NA
> 06? ???17? ???NA
> 
> I need to create a new column for 'mothers age' which puts
> the age of the individual with 'mothers i.d' into the row
> for her offspring (so individual 01 would have 16 in the
> mothers age column, as thats the age of individual 03)
> 
> Hope that makes sense, any help appreciated,
> 
> Thanks
> Laura
> 
> ??? [[alternative HTML version deleted]]
> 
> ______________________________________________
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> 

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