[R] changing a list element's name during execution in lapply - possible?

2010-01-01 Thread Mark Heckmann 

Happy New Year, all!

I want to do calculations on each element of a list l, but i want the  
returned list element to be named differently after the calculation.

Is it possible to do the renaming somehow within the lapply call?

l - list(a=NA, b=NA)
lapply(l, function(x) {names(x) - new name;  return(x) })

This does not work, any ideas?
TIA

–––
Mark Heckmann
Dipl. Wirt.-Ing. cand. Psych.
Vorstraße 93 B01
28359 Bremen
Blog: www.markheckmann.de
R-Blog: http://ryouready.wordpress.com

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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] changing a list element's name during execution in lapply - possible?

2010-01-01 Thread David Winsemius 


On Jan 1, 2010, at 8:21 AM, Mark Heckmann wrote:


Happy New Year, all!

I want to do calculations on each element of a list l, but i want  
the returned list element to be named differently after the  
calculation.

Is it possible to do the renaming somehow within the lapply call?

l - list(a=NA, b=NA)
lapply(l, function(x) {names(x) - new name;  return(x) })

This does not work, any ideas?


It did work in the sense that it created a list of the same  
structure with each node now named new name. If you want that named  
list to become l, then you need to do an assignment:


l - lapply(l, function(x) {names(x) - new name;  return(x) })
 l
$a
new name
  NA

$b
new name
  NA



--
David.


TIA

–––
Mark Heckmann
Dipl. Wirt.-Ing. cand. Psych.
Vorstraße 93 B01


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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] changing a list element's name during execution in lapply - possible?

2010-01-01 Thread Mark Heckmann 
Hi David,

thanks for the answer, though I am not sure what you mean.
My aim is the following out:

input to lapply

  l
$a
[1] NA

$b
[1] NA

output from lapply:
  l
$new_b
[1] NA

$new_b
[1] NA

Mark


Am 01.01.2010 um 14:58 schrieb David Winsemius:


 On Jan 1, 2010, at 8:21 AM, Mark Heckmann wrote:

 Happy New Year, all!

 I want to do calculations on each element of a list l, but i want  
 the returned list element to be named differently after the  
 calculation.
 Is it possible to do the renaming somehow within the lapply call?

  l - list(a=NA, b=NA)
  lapply(l, function(x) {names(x) - new name;  return(x) })

 This does not work, any ideas?

 It did work in the sense that it created a list of the same  
 structure with each node now named new name. If you want that  
 named list to become l, then you need to do an assignment:

 l - lapply(l, function(x) {names(x) - new name;  return(x) })
  l
 $a
 new name
  NA

 $b
 new name
  NA



 -- 
 David.

 TIA

 –––
 Mark Heckmann
 Dipl. Wirt.-Ing. cand. Psych.
 Vorstraße 93 B01

–––
Mark Heckmann
Dipl. Wirt.-Ing. cand. Psych.
Vorstraße 93 B01
28359 Bremen
Blog: www.markheckmann.de
R-Blog: http://ryouready.wordpress.com





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R-help@r-project.org mailing list
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and provide commented, minimal, self-contained, reproducible code.

Re: [R] changing a list element's name during execution in lapply - possible?

2010-01-01 Thread jim holtman 
Is this what you want:

l - list(a=NA, b=NA)
 names(l) - paste(new_, names(l), sep='')
 l
$new_a
[1] NA
$new_b
[1] NA



On Fri, Jan 1, 2010 at 9:48 AM, Mark Heckmann mark.heckm...@gmx.de wrote:

 Hi David,

 thanks for the answer, though I am not sure what you mean.
 My aim is the following out:

 input to lapply

   l
 $a
 [1] NA

 $b
 [1] NA

 output from lapply:
   l
 $new_b
 [1] NA

 $new_b
 [1] NA

 Mark


 Am 01.01.2010 um 14:58 schrieb David Winsemius:

 
  On Jan 1, 2010, at 8:21 AM, Mark Heckmann wrote:
 
  Happy New Year, all!
 
  I want to do calculations on each element of a list l, but i want
  the returned list element to be named differently after the
  calculation.
  Is it possible to do the renaming somehow within the lapply call?
 
   l - list(a=NA, b=NA)
   lapply(l, function(x) {names(x) - new name;  return(x) })
 
  This does not work, any ideas?
 
  It did work in the sense that it created a list of the same
  structure with each node now named new name. If you want that
  named list to become l, then you need to do an assignment:
 
  l - lapply(l, function(x) {names(x) - new name;  return(x) })
   l
  $a
  new name
   NA
 
  $b
  new name
   NA
 
 
 
  --
  David.
 
  TIA
 
  –––
  Mark Heckmann
  Dipl. Wirt.-Ing. cand. Psych.
  Vorstraße 93 B01

 –––
 Mark Heckmann
 Dipl. Wirt.-Ing. cand. Psych.
 Vorstraße 93 B01
 28359 Bremen
 Blog: www.markheckmann.de
 R-Blog: http://ryouready.wordpress.com





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 http://www.R-project.org/posting-guide.htmlhttp://www.r-project.org/posting-guide.html
 and provide commented, minimal, self-contained, reproducible code.




-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?

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and provide commented, minimal, self-contained, reproducible code.

Re: [R] changing a list element's name during execution in lapply - possible?

2010-01-01 Thread Gabor Grothendieck 
Try this:

# same args as lapply.  FUN must return named components.
lapplyWithRename - function(...) {
x - lapply(...)
names(x) - sapply(x, names)
lapply(x, function(x) { names(x) - NULL; x })
}

# test function - if x is A then f returns c(Name A = A)
f - function(x) structure(x, .Names = paste(Name, x))

L - list(a=A, b=B)
lapplyWithRename(L, f)

Output looks like this:
 lapplyWithRename(L, f)
$`Name A`
[1] A

$`Name B`
[1] B


On Fri, Jan 1, 2010 at 8:21 AM, Mark Heckmann mark.heckm...@gmx.de wrote:
 Happy New Year, all!

 I want to do calculations on each element of a list l, but i want the
 returned list element to be named differently after the calculation.
 Is it possible to do the renaming somehow within the lapply call?

        l - list(a=NA, b=NA)
        lapply(l, function(x) {names(x) - new name;  return(x) })

 This does not work, any ideas?
 TIA

 –––
 Mark Heckmann
 Dipl. Wirt.-Ing. cand. Psych.
 Vorstraße 93 B01
 28359 Bremen
 Blog: www.markheckmann.de
 R-Blog: http://ryouready.wordpress.com

 __
 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] changing a list element's name during execution in lapply - possible?

2010-01-01 Thread Mark Heckmann 
Thanks Gabor,
this is what I was looking for.
Mark

Am 01.01.2010 um 16:05 schrieb Gabor Grothendieck:

 Try this:

 # same args as lapply.  FUN must return named components.
 lapplyWithRename - function(...) {
   x - lapply(...)
   names(x) - sapply(x, names)
   lapply(x, function(x) { names(x) - NULL; x })
 }

 # test function - if x is A then f returns c(Name A = A)
 f - function(x) structure(x, .Names = paste(Name, x))

 L - list(a=A, b=B)
 lapplyWithRename(L, f)

 Output looks like this:
 lapplyWithRename(L, f)
 $`Name A`
 [1] A

 $`Name B`
 [1] B


 On Fri, Jan 1, 2010 at 8:21 AM, Mark Heckmann mark.heckm...@gmx.de  
 wrote:
 Happy New Year, all!

 I want to do calculations on each element of a list l, but i want the
 returned list element to be named differently after the calculation.
 Is it possible to do the renaming somehow within the lapply call?

l - list(a=NA, b=NA)
lapply(l, function(x) {names(x) - new name;  return(x) })

 This does not work, any ideas?
 TIA

 –––
 Mark Heckmann
 Dipl. Wirt.-Ing. cand. Psych.
 Vorstraße 93 B01
 28359 Bremen
 Blog: www.markheckmann.de
 R-Blog: http://ryouready.wordpress.com

 __
 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.


–––
Mark Heckmann
Dipl. Wirt.-Ing. cand. Psych.
Vorstraße 93 B01
28359 Bremen
Blog: www.markheckmann.de
R-Blog: http://ryouready.wordpress.com





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__
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.