[R] Multiple merge, better solution?
Hello, My problem is that I would like to merge multiple files with a common column but merge accepts only two data.frames to merge. In the real situation, I have 26 different data.frames with a common column. I can of course use merge many times (see below) but what would be more sophisticated solution? For loop? Any ideas? DF1 - data.frame(var1 = letters[1:5], a = rnorm(5)) DF2 - data.frame(var1 = letters[3:7], b = rnorm(5)) DF3 - data.frame(var1 = letters[6:10], c = rnorm(5)) DF4 - data.frame(var1 = letters[8:12], d = rnorm(5)) g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T) g - merge(g, DF3, by.x=var1, by.y=var1, all=T) merge(g, DF4, by.x=var1, by.y=var1, all=T) Thanks in advance. -Lauri __ R-help@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.
Re: [R] Multiple merge, better solution?
Hi: Below is a TOTAL HACK and I don't recommend it but it does seem to
do what you want. I think that I remember Gabor saying that you can
merge multiple data frames using zoo but I don't know the specifics. I'm
sure he'll respond with the correct way. Below uses a global variable
to access the
dataframe inside the loop and keeps adding on to it. Don't use it unless
you're really desperate for a solution.
DF - DF1
for ( .df in list(DF2,DF3,DF4) ) {
DF-merge(DF,.df,by.x=var1, by.y=var1, all=T)
}
print(DF)
On Thu, Feb 19, 2009 at 5:21 AM, Lauri Nikkinen wrote:
Hello,
My problem is that I would like to merge multiple files with a common
column but merge accepts only two
data.frames to merge. In the real situation, I have 26 different
data.frames with a common column. I can of course use merge many times
(see below) but what would be more sophisticated solution? For loop?
Any ideas?
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5))
DF2 - data.frame(var1 = letters[3:7], b = rnorm(5))
DF3 - data.frame(var1 = letters[6:10], c = rnorm(5))
DF4 - data.frame(var1 = letters[8:12], d = rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
merge(g, DF4, by.x=var1, by.y=var1, all=T)
Thanks in advance.
-Lauri
__
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PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
__
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] Multiple merge, better solution?
Hi, I think Reduce could help you. DF1 - data.frame(var1 = letters[1:5], a = rnorm(5)) DF2 - data.frame(var1 = letters[3:7], b = rnorm(5)) DF3 - data.frame(var1 = letters[6:10], c = rnorm(5)) DF4 - data.frame(var1 = letters[8:12], d = rnorm(5)) g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T) g - merge(g, DF3, by.x=var1, by.y=var1, all=T) g - merge(g, DF4, by.x=var1, by.y=var1, all=T) test - Reduce(function(x, y) merge(x, y, all=T,by.x=var1, by.y=var1), list(DF1, DF2, DF3, DF4), accumulate=F) all.equal(test, g) # TRUE As a warning, it's the first time I've ever used it myself... Hope this helps, baptiste On 19 Feb 2009, at 10:21, Lauri Nikkinen wrote: Hello, My problem is that I would like to merge multiple files with a common column but merge accepts only two data.frames to merge. In the real situation, I have 26 different data.frames with a common column. I can of course use merge many times (see below) but what would be more sophisticated solution? For loop? Any ideas? DF1 - data.frame(var1 = letters[1:5], a = rnorm(5)) DF2 - data.frame(var1 = letters[3:7], b = rnorm(5)) DF3 - data.frame(var1 = letters[6:10], c = rnorm(5)) DF4 - data.frame(var1 = letters[8:12], d = rnorm(5)) g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T) g - merge(g, DF3, by.x=var1, by.y=var1, all=T) merge(g, DF4, by.x=var1, by.y=var1, all=T) Thanks in advance. -Lauri __ R-help@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. _ Baptiste Auguié School of Physics University of Exeter Stocker Road, Exeter, Devon, EX4 4QL, UK Phone: +44 1392 264187 http://newton.ex.ac.uk/research/emag __ R-help@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.
Re: [R] Multiple merge, better solution?
Thanks, both solutions work fine. I tried these solutions to my real
data, and I got an error
Error in match.names(clabs, names(xi)) :
names do not match previous names
I refined this example data to look more like my real data, this also
produces the same error. Any ideas how to prevent this error?
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5), b = rnorm(5), c = rnorm(5))
DF2 - data.frame(var1 = letters[3:7], a = rnorm(5), b = rnorm(5), c = rnorm(5))
DF3 - data.frame(var1 = letters[6:10], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
DF4 - data.frame(var1 = letters[8:12], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
merge(g, DF4, by.x=var1, by.y=var1, all=T)
Error in match.names(clabs, names(xi)) :
names do not match previous names
DF - DF1
for ( .df in list(DF2,DF3,DF4) ) {
+ DF -merge(DF,.df,by.x=var1, by.y=var1, all=T)
+ }
Error in match.names(clabs, names(xi)) :
names do not match previous names
Reduce(function(x, y) merge(x, y, all=T,by.x=var1, by.y=var1), list(DF1,
DF2, DF3, DF4), accumulate=F)
Error in match.names(clabs, names(xi)) :
names do not match previous names
- Lauri
2009/2/19 baptiste auguie ba...@exeter.ac.uk:
Hi,
I think Reduce could help you.
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5))
DF2 - data.frame(var1 = letters[3:7], b = rnorm(5))
DF3 - data.frame(var1 = letters[6:10], c = rnorm(5))
DF4 - data.frame(var1 = letters[8:12], d = rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
g - merge(g, DF4, by.x=var1, by.y=var1, all=T)
test - Reduce(function(x, y) merge(x, y, all=T,by.x=var1, by.y=var1),
list(DF1, DF2, DF3, DF4), accumulate=F)
all.equal(test, g) # TRUE
As a warning, it's the first time I've ever used it myself...
Hope this helps,
baptiste
On 19 Feb 2009, at 10:21, Lauri Nikkinen wrote:
Hello,
My problem is that I would like to merge multiple files with a common
column but merge accepts only two
data.frames to merge. In the real situation, I have 26 different
data.frames with a common column. I can of course use merge many times
(see below) but what would be more sophisticated solution? For loop?
Any ideas?
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5))
DF2 - data.frame(var1 = letters[3:7], b = rnorm(5))
DF3 - data.frame(var1 = letters[6:10], c = rnorm(5))
DF4 - data.frame(var1 = letters[8:12], d = rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
merge(g, DF4, by.x=var1, by.y=var1, all=T)
Thanks in advance.
-Lauri
__
R-help@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.
_
Baptiste Auguié
School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK
Phone: +44 1392 264187
http://newton.ex.ac.uk/research/emag
__
__
R-help@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.
Re: [R] Multiple merge, better solution?
Another option using Recall,
merge.rec - function(.list, ...){
if(length(.list)==1) return(.list[[1]])
Recall(c(list(merge(.list[[1]], .list[[2]], ...)), .list[-(1:2)]), ...)
}
my.list - list(DF1, DF2, DF3, DF4)
test2 - merge.rec(my.list, by.x=var1, by.y=var1, all=T)
all.equal(test2, g)
Note that your second example does not work because in the last step
there are no common names between g and DF4 (I think). Using
suffixes=c(, ) seems to do the trick but I'm not sure it's giving
the result you want/expect.
Hope this helps,
baptiste
On 19 Feb 2009, at 10:21, Lauri Nikkinen wrote:
Hello,
My problem is that I would like to merge multiple files with a common
column but merge accepts only two
data.frames to merge. In the real situation, I have 26 different
data.frames with a common column. I can of course use merge many times
(see below) but what would be more sophisticated solution? For loop?
Any ideas?
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5))
DF2 - data.frame(var1 = letters[3:7], b = rnorm(5))
DF3 - data.frame(var1 = letters[6:10], c = rnorm(5))
DF4 - data.frame(var1 = letters[8:12], d = rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
merge(g, DF4, by.x=var1, by.y=var1, all=T)
Thanks in advance.
-Lauri
__
R-help@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.
_
Baptiste Auguié
School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK
Phone: +44 1392 264187
http://newton.ex.ac.uk/research/emag
__
R-help@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.
Re: [R] Multiple merge, better solution?
If you don't mind I've added this example to the R wiki,
http://wiki.r-project.org/rwiki/doku.php?id=tips:data-frames:merge
It would be very nice if a R guru could check that the information I
put is not complete fantasy. Feel free to remove as appropriate.
Best wishes,
baptiste
On 19 Feb 2009, at 11:00, Lauri Nikkinen wrote:
Thanks, both solutions work fine. I tried these solutions to my real
data, and I got an error
Error in match.names(clabs, names(xi)) :
names do not match previous names
I refined this example data to look more like my real data, this also
produces the same error. Any ideas how to prevent this error?
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
DF2 - data.frame(var1 = letters[3:7], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
DF3 - data.frame(var1 = letters[6:10], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
DF4 - data.frame(var1 = letters[8:12], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
merge(g, DF4, by.x=var1, by.y=var1, all=T)
Error in match.names(clabs, names(xi)) :
names do not match previous names
DF - DF1
for ( .df in list(DF2,DF3,DF4) ) {
+ DF -merge(DF,.df,by.x=var1, by.y=var1, all=T)
+ }
Error in match.names(clabs, names(xi)) :
names do not match previous names
Reduce(function(x, y) merge(x, y, all=T,by.x=var1, by.y=var1),
list(DF1, DF2, DF3, DF4), accumulate=F)
Error in match.names(clabs, names(xi)) :
names do not match previous names
- Lauri
2009/2/19 baptiste auguie ba...@exeter.ac.uk:
Hi,
I think Reduce could help you.
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5))
DF2 - data.frame(var1 = letters[3:7], b = rnorm(5))
DF3 - data.frame(var1 = letters[6:10], c = rnorm(5))
DF4 - data.frame(var1 = letters[8:12], d = rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
g - merge(g, DF4, by.x=var1, by.y=var1, all=T)
test - Reduce(function(x, y) merge(x, y, all=T,by.x=var1,
by.y=var1),
list(DF1, DF2, DF3, DF4), accumulate=F)
all.equal(test, g) # TRUE
As a warning, it's the first time I've ever used it myself...
Hope this helps,
baptiste
On 19 Feb 2009, at 10:21, Lauri Nikkinen wrote:
Hello,
My problem is that I would like to merge multiple files with a
common
column but merge accepts only two
data.frames to merge. In the real situation, I have 26 different
data.frames with a common column. I can of course use merge many
times
(see below) but what would be more sophisticated solution? For loop?
Any ideas?
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5))
DF2 - data.frame(var1 = letters[3:7], b = rnorm(5))
DF3 - data.frame(var1 = letters[6:10], c = rnorm(5))
DF4 - data.frame(var1 = letters[8:12], d = rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
merge(g, DF4, by.x=var1, by.y=var1, all=T)
Thanks in advance.
-Lauri
__
R-help@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.
_
Baptiste Auguié
School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK
Phone: +44 1392 264187
http://newton.ex.ac.uk/research/emag
__
_
Baptiste Auguié
School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK
Phone: +44 1392 264187
http://newton.ex.ac.uk/research/emag
__
R-help@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.
Re: [R] Multiple merge, better solution?
That's perfectly fine. I figured out how to to this with my second example
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5), b = rnorm(5), c = rnorm(5))
DF2 - data.frame(var1 = letters[3:7], a = rnorm(5), b = rnorm(5), c = rnorm(5))
DF3 - data.frame(var1 = letters[6:10], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
DF4 - data.frame(var1 = letters[8:12], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
DF - DF1
for ( .df in list(DF2,DF3,DF4) ) {
DF -merge(DF,.df,by.x=var1, by.y=var1, all=T)
names(DF)[-1] - paste(names(DF)[-1], 2:length(names(DF)))
}
names(DF) - sub([[:space:]].+$, , names(DF), perl=T)
DF
Thank you all!
-Lauri
2009/2/19 baptiste auguie ba...@exeter.ac.uk:
If you don't mind I've added this example to the R wiki,
http://wiki.r-project.org/rwiki/doku.php?id=tips:data-frames:merge
It would be very nice if a R guru could check that the information I put is
not complete fantasy. Feel free to remove as appropriate.
Best wishes,
baptiste
On 19 Feb 2009, at 11:00, Lauri Nikkinen wrote:
Thanks, both solutions work fine. I tried these solutions to my real
data, and I got an error
Error in match.names(clabs, names(xi)) :
names do not match previous names
I refined this example data to look more like my real data, this also
produces the same error. Any ideas how to prevent this error?
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5), b = rnorm(5), c =
rnorm(5))
DF2 - data.frame(var1 = letters[3:7], a = rnorm(5), b = rnorm(5), c =
rnorm(5))
DF3 - data.frame(var1 = letters[6:10], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
DF4 - data.frame(var1 = letters[8:12], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
merge(g, DF4, by.x=var1, by.y=var1, all=T)
Error in match.names(clabs, names(xi)) :
names do not match previous names
DF - DF1
for ( .df in list(DF2,DF3,DF4) ) {
+ DF -merge(DF,.df,by.x=var1, by.y=var1, all=T)
+ }
Error in match.names(clabs, names(xi)) :
names do not match previous names
Reduce(function(x, y) merge(x, y, all=T,by.x=var1, by.y=var1),
list(DF1, DF2, DF3, DF4), accumulate=F)
Error in match.names(clabs, names(xi)) :
names do not match previous names
- Lauri
2009/2/19 baptiste auguie ba...@exeter.ac.uk:
Hi,
I think Reduce could help you.
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5))
DF2 - data.frame(var1 = letters[3:7], b = rnorm(5))
DF3 - data.frame(var1 = letters[6:10], c = rnorm(5))
DF4 - data.frame(var1 = letters[8:12], d = rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
g - merge(g, DF4, by.x=var1, by.y=var1, all=T)
test - Reduce(function(x, y) merge(x, y, all=T,by.x=var1,
by.y=var1),
list(DF1, DF2, DF3, DF4), accumulate=F)
all.equal(test, g) # TRUE
As a warning, it's the first time I've ever used it myself...
Hope this helps,
baptiste
On 19 Feb 2009, at 10:21, Lauri Nikkinen wrote:
Hello,
My problem is that I would like to merge multiple files with a common
column but merge accepts only two
data.frames to merge. In the real situation, I have 26 different
data.frames with a common column. I can of course use merge many times
(see below) but what would be more sophisticated solution? For loop?
Any ideas?
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5))
DF2 - data.frame(var1 = letters[3:7], b = rnorm(5))
DF3 - data.frame(var1 = letters[6:10], c = rnorm(5))
DF4 - data.frame(var1 = letters[8:12], d = rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
merge(g, DF4, by.x=var1, by.y=var1, all=T)
Thanks in advance.
-Lauri
__
R-help@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.
_
Baptiste Auguié
School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK
Phone: +44 1392 264187
http://newton.ex.ac.uk/research/emag
__
_
Baptiste Auguié
School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK
Phone: +44 1392 264187
http://newton.ex.ac.uk/research/emag
__
__
R-help@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.
Re: [R] Multiple merge, better solution?
Yes, even better
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5), b = rnorm(5), c = rnorm(5))
DF2 - data.frame(var1 = letters[3:7], a = rnorm(5), b = rnorm(5), c = rnorm(5))
DF3 - data.frame(var1 = letters[6:10], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
DF4 - data.frame(var1 = letters[8:12], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
DF - DF1
for ( .df in list(DF2,DF3,DF4) ) {
DF -merge(DF,.df,by.x=var1, by.y=var1, all=T, suffixes=c(, ))
}
DF
-Lauri
2009/2/19 Lauri Nikkinen lauri.nikki...@iki.fi:
That's perfectly fine. I figured out how to to this with my second example
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5), b = rnorm(5), c =
rnorm(5))
DF2 - data.frame(var1 = letters[3:7], a = rnorm(5), b = rnorm(5), c =
rnorm(5))
DF3 - data.frame(var1 = letters[6:10], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
DF4 - data.frame(var1 = letters[8:12], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
DF - DF1
for ( .df in list(DF2,DF3,DF4) ) {
DF -merge(DF,.df,by.x=var1, by.y=var1, all=T)
names(DF)[-1] - paste(names(DF)[-1], 2:length(names(DF)))
}
names(DF) - sub([[:space:]].+$, , names(DF), perl=T)
DF
Thank you all!
-Lauri
2009/2/19 baptiste auguie ba...@exeter.ac.uk:
If you don't mind I've added this example to the R wiki,
http://wiki.r-project.org/rwiki/doku.php?id=tips:data-frames:merge
It would be very nice if a R guru could check that the information I put is
not complete fantasy. Feel free to remove as appropriate.
Best wishes,
baptiste
On 19 Feb 2009, at 11:00, Lauri Nikkinen wrote:
Thanks, both solutions work fine. I tried these solutions to my real
data, and I got an error
Error in match.names(clabs, names(xi)) :
names do not match previous names
I refined this example data to look more like my real data, this also
produces the same error. Any ideas how to prevent this error?
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5), b = rnorm(5), c =
rnorm(5))
DF2 - data.frame(var1 = letters[3:7], a = rnorm(5), b = rnorm(5), c =
rnorm(5))
DF3 - data.frame(var1 = letters[6:10], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
DF4 - data.frame(var1 = letters[8:12], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
merge(g, DF4, by.x=var1, by.y=var1, all=T)
Error in match.names(clabs, names(xi)) :
names do not match previous names
DF - DF1
for ( .df in list(DF2,DF3,DF4) ) {
+ DF -merge(DF,.df,by.x=var1, by.y=var1, all=T)
+ }
Error in match.names(clabs, names(xi)) :
names do not match previous names
Reduce(function(x, y) merge(x, y, all=T,by.x=var1, by.y=var1),
list(DF1, DF2, DF3, DF4), accumulate=F)
Error in match.names(clabs, names(xi)) :
names do not match previous names
- Lauri
2009/2/19 baptiste auguie ba...@exeter.ac.uk:
Hi,
I think Reduce could help you.
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5))
DF2 - data.frame(var1 = letters[3:7], b = rnorm(5))
DF3 - data.frame(var1 = letters[6:10], c = rnorm(5))
DF4 - data.frame(var1 = letters[8:12], d = rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
g - merge(g, DF4, by.x=var1, by.y=var1, all=T)
test - Reduce(function(x, y) merge(x, y, all=T,by.x=var1,
by.y=var1),
list(DF1, DF2, DF3, DF4), accumulate=F)
all.equal(test, g) # TRUE
As a warning, it's the first time I've ever used it myself...
Hope this helps,
baptiste
On 19 Feb 2009, at 10:21, Lauri Nikkinen wrote:
Hello,
My problem is that I would like to merge multiple files with a common
column but merge accepts only two
data.frames to merge. In the real situation, I have 26 different
data.frames with a common column. I can of course use merge many times
(see below) but what would be more sophisticated solution? For loop?
Any ideas?
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5))
DF2 - data.frame(var1 = letters[3:7], b = rnorm(5))
DF3 - data.frame(var1 = letters[6:10], c = rnorm(5))
DF4 - data.frame(var1 = letters[8:12], d = rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
merge(g, DF4, by.x=var1, by.y=var1, all=T)
Thanks in advance.
-Lauri
__
R-help@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.
_
Baptiste Auguié
School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK
Phone: +44 1392 264187
http://newton.ex.ac.uk/research/emag
__
_
Baptiste Auguié
School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK
Phone: +44 1392 264187
http://newton.ex.ac.uk/research/emag
Re: [R] Multiple merge, better solution?
The zoo package has a multi-way merge for zoo objects. Its
just do.call(merge, z) where z is a list of zoo objects.
In detail:
set.seed(1)
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5), b = rnorm(5), c = rnorm(5))
DF2 - data.frame(var1 = letters[3:7], a = rnorm(5), b = rnorm(5), c = rnorm(5))
DF3 - data.frame(var1 = letters[6:10], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
DF4 - data.frame(var1 = letters[8:12], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
# create list of data frames
DFs - list(A = DF1, B = DF2, C = DF3, D = DF4)
library(zoo)
# convert to list of zoo objects
z - lapply(DFs, function(x) zoo(as.matrix(x[ ,-1, drop = FALSE]),
as.character(x[,1])))
# perform merge
zz - do.call(merge, z)
# to convert back to data frame
DF - as.data.frame(var1 = time(zz), coredata(zz))
On Thu, Feb 19, 2009 at 6:00 AM, Lauri Nikkinen lauri.nikki...@iki.fi wrote:
Thanks, both solutions work fine. I tried these solutions to my real
data, and I got an error
Error in match.names(clabs, names(xi)) :
names do not match previous names
I refined this example data to look more like my real data, this also
produces the same error. Any ideas how to prevent this error?
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5), b = rnorm(5), c =
rnorm(5))
DF2 - data.frame(var1 = letters[3:7], a = rnorm(5), b = rnorm(5), c =
rnorm(5))
DF3 - data.frame(var1 = letters[6:10], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
DF4 - data.frame(var1 = letters[8:12], a = rnorm(5), b = rnorm(5), c
= rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
merge(g, DF4, by.x=var1, by.y=var1, all=T)
Error in match.names(clabs, names(xi)) :
names do not match previous names
DF - DF1
for ( .df in list(DF2,DF3,DF4) ) {
+ DF -merge(DF,.df,by.x=var1, by.y=var1, all=T)
+ }
Error in match.names(clabs, names(xi)) :
names do not match previous names
Reduce(function(x, y) merge(x, y, all=T,by.x=var1, by.y=var1), list(DF1,
DF2, DF3, DF4), accumulate=F)
Error in match.names(clabs, names(xi)) :
names do not match previous names
- Lauri
2009/2/19 baptiste auguie ba...@exeter.ac.uk:
Hi,
I think Reduce could help you.
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5))
DF2 - data.frame(var1 = letters[3:7], b = rnorm(5))
DF3 - data.frame(var1 = letters[6:10], c = rnorm(5))
DF4 - data.frame(var1 = letters[8:12], d = rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
g - merge(g, DF4, by.x=var1, by.y=var1, all=T)
test - Reduce(function(x, y) merge(x, y, all=T,by.x=var1, by.y=var1),
list(DF1, DF2, DF3, DF4), accumulate=F)
all.equal(test, g) # TRUE
As a warning, it's the first time I've ever used it myself...
Hope this helps,
baptiste
On 19 Feb 2009, at 10:21, Lauri Nikkinen wrote:
Hello,
My problem is that I would like to merge multiple files with a common
column but merge accepts only two
data.frames to merge. In the real situation, I have 26 different
data.frames with a common column. I can of course use merge many times
(see below) but what would be more sophisticated solution? For loop?
Any ideas?
DF1 - data.frame(var1 = letters[1:5], a = rnorm(5))
DF2 - data.frame(var1 = letters[3:7], b = rnorm(5))
DF3 - data.frame(var1 = letters[6:10], c = rnorm(5))
DF4 - data.frame(var1 = letters[8:12], d = rnorm(5))
g - merge(DF1, DF2, by.x=var1, by.y=var1, all=T)
g - merge(g, DF3, by.x=var1, by.y=var1, all=T)
merge(g, DF4, by.x=var1, by.y=var1, all=T)
Thanks in advance.
-Lauri
__
R-help@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.
_
Baptiste Auguié
School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK
Phone: +44 1392 264187
http://newton.ex.ac.uk/research/emag
__
__
R-help@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.
__
R-help@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.
