[R] assign value to multiple objects with a given ls pattern
Dear R colleagues, This seems pretty straight forward but I have been banging my head on this for some time and can't seem to find a solution suppose I have something like a1-1; a2-2; a3-3; a4-4; b1-3; b2-4 I would like to quickly assign to objects with a certain pattern, e.g., those in ls(pattern=a) a specific value, e.g., 99, without having to assign each object at a time. is there a way I can do this within a for cycle? I have tested several eval and parse statements but with no success. Regards, Nuno Prista PhD student Instituto de Oceanografia Faculdade de Ciências da Universidade de Lisboa Campo Grande, Lisboa, 1749-016 Lisboa, Portugal __ 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] assign value to multiple objects with a given ls pattern
Hi Nuno,
Yes, you can do
for(i in ls(pattern=a))
{
assign(i, 99)
}
but honestly this is a bad idea. It will try to assign the value of 99
to any object in your workspace that contains an a, which sounds
really scary to me.
Better I think to use a list:
ab.list - list(a1=1, a2=2, a3=3, a4=4, b1=3, b2=4)
ab.list[grep(a, names(ab.list))] - 99
Or even just a named vector
ab.vector - c(a1=1, a2=2, a3=3, a4=4, b1=3, b2=4)
ab.vector[grep(a, names(ab.vector))] - 99
Best,
Ista
On Mon, Feb 21, 2011 at 4:22 PM, Nuno Prista nmpri...@fc.ul.pt wrote:
Dear R colleagues,
This seems pretty straight forward but I have been banging my head on this
for some time and can't seem to find a solution
suppose I have something like
a1-1; a2-2; a3-3; a4-4; b1-3; b2-4
I would like to quickly assign to objects with a certain pattern, e.g., those
in
ls(pattern=a)
a specific value, e.g., 99, without having to assign each object at a time.
is there a way I can do this within a for cycle? I have tested several eval
and parse statements but with no success.
Regards,
Nuno Prista
PhD student
Instituto de Oceanografia
Faculdade de Ciências da Universidade de Lisboa
Campo Grande, Lisboa,
1749-016 Lisboa,
Portugal
__
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.
--
Ista Zahn
Graduate student
University of Rochester
Department of Clinical and Social Psychology
http://yourpsyche.org
__
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] assign value to multiple objects with a given ls pattern
Hi, This works for me: pat - ls(pattern=^a) ## I would anchor a to the beginning with ^ for safety! for (i in seq_along(pat))assign(pat[i], value=99) Or this with lapply: lapply(pat, FUN=function(x) assign(x, value=99, envir=.GlobalEnv)) See ?assign HTH, Ivan Le 2/21/2011 17:22, Nuno Prista a écrit : Dear R colleagues, This seems pretty straight forward but I have been banging my head on this for some time and can't seem to find a solution suppose I have something like a1-1; a2-2; a3-3; a4-4; b1-3; b2-4 I would like to quickly assign to objects with a certain pattern, e.g., those in ls(pattern=a) a specific value, e.g., 99, without having to assign each object at a time. is there a way I can do this within a for cycle? I have tested several eval and parse statements but with no success. Regards, Nuno Prista PhD student Instituto de Oceanografia Faculdade de Ciências da Universidade de Lisboa Campo Grande, Lisboa, 1749-016 Lisboa, Portugal __ 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/1525_8_1.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] assign value to multiple objects with a given ls pattern
If instead of having a1, a2, etc. as global variables you put them into a list then this becomes simple. The general rule is that if you ever want to do the same (or similar) think to a set of variable, then they should not have been separate variables, but part of a bigger one. Lists work well for this (there are other possibilities as well, but lists cover most of the cases). -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.s...@imail.org 801.408.8111 -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- project.org] On Behalf Of Nuno Prista Sent: Monday, February 21, 2011 9:22 AM To: r-help@R-project.org Subject: [R] assign value to multiple objects with a given ls pattern Dear R colleagues, This seems pretty straight forward but I have been banging my head on this for some time and can't seem to find a solution suppose I have something like a1-1; a2-2; a3-3; a4-4; b1-3; b2-4 I would like to quickly assign to objects with a certain pattern, e.g., those in ls(pattern=a) a specific value, e.g., 99, without having to assign each object at a time. is there a way I can do this within a for cycle? I have tested several eval and parse statements but with no success. Regards, Nuno Prista PhD student Instituto de Oceanografia Faculdade de Ciências da Universidade de Lisboa Campo Grande, Lisboa, 1749-016 Lisboa, Portugal __ 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] assign value to multiple objects with a given ls pattern
As I partially showed, I guess that the problem of assigning the value
99 to any object in the workspace can be dealt with a more precise
regular expression.
Maybe that would do:
ls(pattern=^a[1-9]$)
or
ls(pattern=^a[0-9]+$)
In any case, I agree that alternatives are better
Ivan
Le 2/21/2011 17:55, Ista Zahn a écrit :
Hi Nuno,
Yes, you can do
for(i in ls(pattern=a))
{
assign(i, 99)
}
but honestly this is a bad idea. It will try to assign the value of 99
to any object in your workspace that contains an a, which sounds
really scary to me.
Better I think to use a list:
ab.list- list(a1=1, a2=2, a3=3, a4=4, b1=3, b2=4)
ab.list[grep(a, names(ab.list))]- 99
Or even just a named vector
ab.vector- c(a1=1, a2=2, a3=3, a4=4, b1=3, b2=4)
ab.vector[grep(a, names(ab.vector))]- 99
Best,
Ista
On Mon, Feb 21, 2011 at 4:22 PM, Nuno Pristanmpri...@fc.ul.pt wrote:
Dear R colleagues,
This seems pretty straight forward but I have been banging my head on this for
some time and can't seem to find a solution
suppose I have something like
a1-1; a2-2; a3-3; a4-4; b1-3; b2-4
I would like to quickly assign to objects with a certain pattern, e.g., those in
ls(pattern=a)
a specific value, e.g., 99, without having to assign each object at a time.
is there a way I can do this within a for cycle? I have tested several eval
and parse statements but with no success.
Regards,
Nuno Prista
PhD student
Instituto de Oceanografia
Faculdade de Ciências da Universidade de Lisboa
Campo Grande, Lisboa,
1749-016 Lisboa,
Portugal
__
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/1525_8_1.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.
