Thanks to all who replied.
Here are two versions of a function (sans sanity checks) that do what I
want:
foo1 <- multifoo(1:2, "A")
foo2 <- multifoo(1:2, "B")
mfoo <- list(A=foo1, B=foo2)
class(mfoo) <- c("foolist", "list")
#' flatten a list of lists
# from Duncan Murdoch
flatten <- function(list, unname=TRUE) {
res <- do.call(c, if(unname) unname(list) else list)
class(res) <- class(list)
res
}
# from David Carlson
flatten2 <- function(list, unname=TRUE) {
res <- unlist(list, recursive = FALSE)
if(unname) names(res) <- unlist(lapply(list, names))
class(res) <- class(list)
res
}
mflat1 <- flatten(mfoo)
mflat2 <- flatten2(mfoo)
all.equal(mflat1,mflat2)
> all.equal(mflat1,mflat2)
[1] TRUE
-Michael
On 10/17/2013 9:39 AM, David Carlson wrote:
Does this get you the rest of the way?
mfoo2 <- unlist(mfoo, recursive = FALSE)
names(mfoo2) <- unlist(lapply(mfoo, names))
class(mfoo2) <- "foolist"
str(mfoo2)
List of 4
$ A1:List of 2
..$ x: int 3
..$ y: int 10
..- attr(*, "class")= chr "foo"
$ A2:List of 2
..$ x: int [1:2] 6 4
..$ y: int [1:2] 8 9
..- attr(*, "class")= chr "foo"
$ B1:List of 2
..$ x: int 2
..$ y: int 2
..- attr(*, "class")= chr "foo"
$ B2:List of 2
..$ x: int [1:2] 3 6
..$ y: int [1:2] 4 2
..- attr(*, "class")= chr "foo"
- attr(*, "class")= chr "foolist"
-------------------------------------
David L Carlson
Department of Anthropology
Texas A&M University
College Station, TX 77840-4352
-----Original Message-----
From: r-help-boun...@r-project.org
[mailto:r-help-boun...@r-project.org] On Behalf Of Ista Zahn
Sent: Thursday, October 17, 2013 8:23 AM
To: Michael Friendly
Cc: R-help
Subject: Re: [R] flatten a list of lists
unlist(mfoo, recursive = FALSE) gets you pretty close.
Best,
Ista
On Thu, Oct 17, 2013 at 9:15 AM, Michael Friendly
<frien...@yorku.ca> wrote:
I have functions that generate lists objects of class "foo"
and lists of
lists of these, of class
"foolist", similar to what is shown below.
How can I flatten something like this to remove the top-level
list
structure, i.e.,
return a single-level list of "foo" objects, of class
"foolist"?
foo <- function(n) {
result <- list(x=sample(1:10,n), y=sample(1:10,n))
class(result) <- "foo"
result
}
multifoo <- function(vec, label, ...) {
result <- lapply(vec, foo, ...)
names(result) <- paste0(label, vec)
class(result) <- "foolist"
result
}
foo1 <- multifoo(1:2, "A")
foo2 <- multifoo(1:2, "B")
mfoo <- list(A=foo1, B=foo2)
str(mfoo, 2)
str(mfoo, 2)
List of 2
$ A:List of 2
..$ A1:List of 2
.. ..- attr(*, "class")= chr "foo"
..$ A2:List of 2
.. ..- attr(*, "class")= chr "foo"
..- attr(*, "class")= chr "foolist"
$ B:List of 2
..$ B1:List of 2
.. ..- attr(*, "class")= chr "foo"
..$ B2:List of 2
.. ..- attr(*, "class")= chr "foo"
..- attr(*, "class")= chr "foolist"
In this case, what is wanted is a single-level list, of 4 foo
objects, A1,
A2, B1, B2,
all of class "foolist"
--
Michael Friendly Email: friendly AT yorku DOT ca
Professor, Psychology Dept. & Chair, Quantitative Methods
York University Voice: 416 736-2100 x66249 Fax: 416
736-5814
4700 Keele Street Web: http://www.datavis.ca
Toronto, ONT M3J 1P3 CANADA
______________________________________________
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.
--
Michael Friendly Email: friendly AT yorku DOT ca
Professor, Psychology Dept. & Chair, Quantitative Methods
York University Voice: 416 736-2100 x66249 Fax: 416 736-5814
4700 Keele Street Web: http://www.datavis.ca
Toronto, ONT M3J 1P3 CANADA
______________________________________________
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.
