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 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 :
>> 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.
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 :
> 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 :
>> 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 :
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
> a
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 :
> 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 :
>>>
>>> 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.o
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 :
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?
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
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_
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
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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 :
> 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
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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?
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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and provide commented, minimal, self-contained, reproducible code.
