[R] How to get a specific named element in a nested list
Hello, I have a nested named list structure, like the following: x - list( list( list(df1,df2) list(df3, list(df4,df5)) list(df6,df7))) with df1...d7 as data frames. Every data frame is named. Is there a way to get a specific named element in x? so, for example, x[[c(df5)]] gives me the data frame 5? Thank you in advance! Best, Friedericksen __ 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] How to get a specific named element in a nested list
Hi, A reproducible example would have been nice, but a correct code even more (you forgot some commas)! So if you meant this: x - list( list( list(df1,df2), list(df3, list(df4,df5)), list(df6,df7))) check str(x): (I removes the details of each df) List of 1 $ :List of 3 ..$ :List of 2 .. ..$ :'data.frame': 10 obs. of 2 variables: ## df1 .. ..$ :'data.frame': 10 obs. of 2 variables: ## df2 ..$ :List of 2 .. ..$ :'data.frame': 10 obs. of 2 variables: ## df3 .. ..$ :List of 2 .. .. ..$ :'data.frame': 10 obs. of 2 variables: ## df4 .. .. ..$ :'data.frame': 10 obs. of 2 variables: ## df5 ..$ :List of 2 .. ..$ :'data.frame': 10 obs. of 2 variables:## df6 .. ..$ :'data.frame': 10 obs. of 2 variables:## df7 And check x: (I removed the details again) [[1]] [[1]][[1]] [[1]][[1]][[1]] df1 [[1]][[1]][[2]] df2 [[1]][[2]] [[1]][[2]][[1]] df3 [[1]][[2]][[2]] [[1]][[2]][[2]][[1]] df4 [[1]][[2]][[2]][[2]] df5 [[1]][[3]] [[1]][[3]][[1]] df6 [[1]][[3]][[2]] df7 If you want to access them, you need to follow the structure of your list, e.g. for df1: x[[1]][[1]][[1]] for df5: x[[1]][[2]][[2]][[2]] You need to access them with indexes because the list elements are unnamed. Now if you do: x - list(uppermost=list( medium1=list(df1=df1,df2=df2), medium2=list(df3=df3, lowermost=list(df4=df4,df5=df5)), medium3=list(df6=df6,df7=df7))) You can access them with names (but you still need to follow the structure, i.e. x[[df5]] cannot work): For df1: x$uppermost$medium1$df1 or x[[uppermost]][[medium1]][[df1]] for df5: x$uppermost$medium2$lowermost$df5or x[[uppermost]][[medium2]][[lowermost]][[df5]] But I guess you can write a function that would search through the structure of x for a given df (that has to be named then) and return it. Maybe you have your reasons to have such a complicated list, but if it were me, I would make it easier to understand and to access (i.e. less nested, max 2 levels) HTH, Ivan Le 11/11/2010 09:05, Friedericksen Hope a écrit : Hello, I have a nested named list structure, like the following: x - list( list( list(df1,df2) list(df3, list(df4,df5)) list(df6,df7))) with df1...d7 as data frames. Every data frame is named. Is there a way to get a specific named element in x? so, for example, x[[c(df5)]] gives me the data frame 5? Thank you in advance! Best, Friedericksen __ 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. -- Ivan CALANDRA PhD Student University of Hamburg Biozentrum Grindel und Zoologisches Museum Abt. Säugetiere Martin-Luther-King-Platz 3 D-20146 Hamburg, GERMANY +49(0)40 42838 6231 ivan.calan...@uni-hamburg.de ** http://www.for771.uni-bonn.de http://webapp5.rrz.uni-hamburg.de/mammals/eng/mitarbeiter.php __ 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] How to get a specific named element in a nested list
Hi Friedericksen,
This function will do it. No doubt there are more elegant ways :)
rmatch - function(x, name) {
pos - match(name, names(x))
if (!is.na(pos))
return(x[[pos]])
for (el in x) {
if (class(el) == list) {
out - getEl(el, name)
if (!is.null(out)) return(out)
}
}
}
Michael
On 11 November 2010 19:05, Friedericksen Hope
friedericksen.h...@gmail.com wrote:
Hello,
I have a nested named list structure, like the following:
x - list(
list(
list(df1,df2)
list(df3,
list(df4,df5))
list(df6,df7)))
with df1...d7 as data frames. Every data frame is named.
Is there a way to get a specific named element in x?
so, for example,
x[[c(df5)]] gives me the data frame 5?
Thank you in advance!
Best,
Friedericksen
__
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] How to get a specific named element in a nested list
What you want is some sort of indexing nested lists based on names (as we
are used to for vectors, for example). As Ivan pointed out, I don't think
there's an out-of-the-box function in R that supports such indexing as it
requires some sort of mapping of the nested list's hierarchical structure.
At first I thought one could use the information of 'as.relistable()' and
'relist()' in some way, but I couldn't really make use of it.
So this is my own solution for retrieving all branch names of an arbitrary
deeply nested list together with their recursive indexes which you then can
use to index/access a branch of your choice. I'm sure there are more elegant
ways, but at least it does the trick ;-). Currently requires that all
branches are named and names at a branch are unique(!). E.g., this is fine:
my.list=list(a=list(a.1=list(...), a.2=list(...)), b=list(...)); something
like this is not supported yet: my.list=list(a=list(a.1=list(...),
a.1=list(...)), a=list(...))). One could use regular expressions to handle
stubs of names. Right now you must use the absolute path name (e.g.
a$a.1$a.1.1) of a branch to access it (you get this info via
'listnames.get()', though). But it should be easy to handle stubs (e.g.
a.1.1 only) as well.
The two function defs and an example:
# FUNCTION DEFS #
listnames.get - function(
list.obj,
do.basename=FALSE,
do.name.chain=TRUE,
...
)
{
# VALIDATE
if(!is.list(list.obj)) stop(Argument 'list.obj' must be a list.)
# /
#---
# CORE FUNCTION
#---
listnames.get.core - function(
# CUSTOM:
list.obj,
do.basename=FALSE,
do.name.chain=TRUE,
buffer,
...
)
{
if(!exists(index, buffer))
{
buffer$index- new.env(parent=emptyenv())
buffer$index- NULL
buffer$name - NULL
}
#x=1
jnk - sapply(1:length(list.obj), function(x)
{
list.branch - list.obj[x]
list.branch.nme - names(list.branch)
if(do.basename) list.branch.nme -
basename(list.branch.nme)
list.obj.updt - list.branch[[1]]
# UPDATE BUFFER
buffer$run - c(buffer$run, x)
if(do.name.chain)
{
# buffer$name -
paste(buffer$name, list.branch.nme, sep=$)
buffer$name - c(buffer$name,
list.branch.nme)
} else
{
buffer$name - list.branch.nme
}
# /
index.crnt -
paste(as.character(buffer$run), collapse=-)
index.crnt - data.frame(
name=paste(buffer$name, collapse=$),
index=index.crnt,
stringsAsFactors=FALSE
)
index.updt - rbind(buffer$index,
index.crnt)
buffer$index- index.updt
if(is.list(list.obj.updt))
{
listnames.get.core(
list.obj=list.obj.updt,
do.basename=do.basename,
do.name.chain=do.name.chain,
buffer=buffer
)
}
# UPDATE BUFFER
buffer$run - buffer$run[-length(buffer$run)]
buffer$name - buffer$name[-length(buffer$name)]
# /
return(NULL)
})
return(TRUE)
}
# /CORE FUNCTION --
#---
# APPLICATION
#---
assign(buffer, new.env(parent=emptyenv()), envir=environment())
listnames.get.core(
Re: [R] How to get a specific named element in a nested list
Hi Ivan, thank you very much for your detailed explanations and response! Please excuse, that I did not include a reproducible example. Yes, what I am looking for is such a function - but I suspect, that it does not exist already, so I have to write it on my own. Best, Friedericksen On 11/11/2010 10:23 AM, Ivan Calandra wrote: Hi, A reproducible example would have been nice, but a correct code even more (you forgot some commas)! So if you meant this: x - list( list( list(df1,df2), list(df3, list(df4,df5)), list(df6,df7))) check str(x): (I removes the details of each df) List of 1 $ :List of 3 ..$ :List of 2 .. ..$ :'data.frame': 10 obs. of 2 variables: ## df1 .. ..$ :'data.frame': 10 obs. of 2 variables: ## df2 ..$ :List of 2 .. ..$ :'data.frame': 10 obs. of 2 variables: ## df3 .. ..$ :List of 2 .. .. ..$ :'data.frame': 10 obs. of 2 variables: ## df4 .. .. ..$ :'data.frame': 10 obs. of 2 variables: ## df5 ..$ :List of 2 .. ..$ :'data.frame': 10 obs. of 2 variables: ## df6 .. ..$ :'data.frame': 10 obs. of 2 variables: ## df7 And check x: (I removed the details again) [[1]] [[1]][[1]] [[1]][[1]][[1]] df1 [[1]][[1]][[2]] df2 [[1]][[2]] [[1]][[2]][[1]] df3 [[1]][[2]][[2]] [[1]][[2]][[2]][[1]] df4 [[1]][[2]][[2]][[2]] df5 [[1]][[3]] [[1]][[3]][[1]] df6 [[1]][[3]][[2]] df7 If you want to access them, you need to follow the structure of your list, e.g. for df1: x[[1]][[1]][[1]] for df5: x[[1]][[2]][[2]][[2]] You need to access them with indexes because the list elements are unnamed. Now if you do: x - list(uppermost=list( medium1=list(df1=df1,df2=df2), medium2=list(df3=df3, lowermost=list(df4=df4,df5=df5)), medium3=list(df6=df6,df7=df7))) You can access them with names (but you still need to follow the structure, i.e. x[[df5]] cannot work): For df1: x$uppermost$medium1$df1 or x[[uppermost]][[medium1]][[df1]] for df5: x$uppermost$medium2$lowermost$df5 or x[[uppermost]][[medium2]][[lowermost]][[df5]] But I guess you can write a function that would search through the structure of x for a given df (that has to be named then) and return it. Maybe you have your reasons to have such a complicated list, but if it were me, I would make it easier to understand and to access (i.e. less nested, max 2 levels) HTH, Ivan Le 11/11/2010 09:05, Friedericksen Hope a écrit : Hello, I have a nested named list structure, like the following: x - list( list( list(df1,df2) list(df3, list(df4,df5)) list(df6,df7))) with df1...d7 as data frames. Every data frame is named. Is there a way to get a specific named element in x? so, for example, x[[c(df5)]] gives me the data frame 5? Thank you in advance! Best, Friedericksen __ 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] How to get a specific named element in a nested list
On 11 November 2010 21:08, Janko Thyson janko.thy...@ku-eichstaett.de wrote:
Could it be that you forgot to supply 'getEL()'? Or do I have to use some
package to make it available?
Oops - no. The problem was me stupidly renaming the function without
modifying the code. Try this instead...
rmatch - function(x, name) {
pos - match(name, names(x))
if (!is.na(pos))
return(x[[pos]])
for (el in x) {
if (class(el) == list) {
out - rmatch(el, name)
if (!is.null(out)) return(out)
}
}
}
Sorry about that.
Michael
-Ursprüngliche Nachricht-
Von: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] Im
Auftrag von Michael Bedward
Gesendet: Donnerstag, 11. November 2010 10:56
An: friedericksen.h...@gmail.com
Cc: r-h...@stat.math.ethz.ch
Betreff: Re: [R] How to get a specific named element in a nested list
Hi Friedericksen,
This function will do it. No doubt there are more elegant ways :)
rmatch - function(x, name) {
pos - match(name, names(x))
if (!is.na(pos))
return(x[[pos]])
for (el in x) {
if (class(el) == list) {
out - getEl(el, name)
if (!is.null(out)) return(out)
}
}
}
Michael
On 11 November 2010 19:05, Friedericksen Hope
friedericksen.h...@gmail.com wrote:
Hello,
I have a nested named list structure, like the following:
x - list(
list(
list(df1,df2)
list(df3,
list(df4,df5))
list(df6,df7)))
with df1...d7 as data frames. Every data frame is named.
Is there a way to get a specific named element in x?
so, for example,
x[[c(df5)]] gives me the data frame 5?
Thank you in advance!
Best,
Friedericksen
__
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.
__
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] How to get a specific named element in a nested list
Neat!
I think replacing
out - rmatch(el, name)
with
out - Recall(el, name)
will avoid the dependence of the code on the function name
Keith J
Michael Bedward michael.bedw...@gmail.com wrote in message
news:aanlktikv9zepxipbp7ftr8vmpgsjaptjyj_dudy-m...@mail.gmail.com...
On 11 November 2010 21:08, Janko Thyson janko.thy...@ku-eichstaett.de
wrote:
Could it be that you forgot to supply 'getEL()'? Or do I have to use some
package to make it available?
Oops - no. The problem was me stupidly renaming the function without
modifying the code. Try this instead...
rmatch - function(x, name) {
pos - match(name, names(x))
if (!is.na(pos))
return(x[[pos]])
for (el in x) {
if (class(el) == list) {
out - rmatch(el, name)
if (!is.null(out)) return(out)
}
}
}
Sorry about that.
Michael
-Ursprüngliche Nachricht-
Von: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org]
Im
Auftrag von Michael Bedward
Gesendet: Donnerstag, 11. November 2010 10:56
An: friedericksen.h...@gmail.com
Cc: r-h...@stat.math.ethz.ch
Betreff: Re: [R] How to get a specific named element in a nested list
Hi Friedericksen,
This function will do it. No doubt there are more elegant ways :)
rmatch - function(x, name) {
pos - match(name, names(x))
if (!is.na(pos))
return(x[[pos]])
for (el in x) {
if (class(el) == list) {
out - getEl(el, name)
if (!is.null(out)) return(out)
}
}
}
Michael
On 11 November 2010 19:05, Friedericksen Hope
friedericksen.h...@gmail.com wrote:
Hello,
I have a nested named list structure, like the following:
x - list(
list(
list(df1,df2)
list(df3,
list(df4,df5))
list(df6,df7)))
with df1...d7 as data frames. Every data frame is named.
Is there a way to get a specific named element in x?
so, for example,
x[[c(df5)]] gives me the data frame 5?
Thank you in advance!
Best,
Friedericksen
__
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.
__
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.
