Re: [R] How to insert one element into a vector?
On Mon, 2004-11-22 at 17:43, Barry Rowlingson wrote: Deepayan Sarkar wrote: Pretty much what 'append' does. A shame then, that help.search(insert) doesn't find 'append'! I cant think why anyone looking for a way of _inserting_ a value in the middle of a vector would think of looking at append! Python has separate insert and append methods for vectors. x=[1,2,3,4,6] x.insert(4,5) x [1, 2, 3, 4, 5, 6] x.append(99) x [1, 2, 3, 4, 5, 6, 99] So has R. R's 'insert' is called 'append', and R's 'append' is called 'c'. Counter-intuitively though, and I'm happy that Peter Dalgaard didn't know that 'append' inserts: it gives some hope to us ordinary mortals. cheers, jazza -- Jari Oksanen [EMAIL PROTECTED] __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
RE: [R] How to insert one element into a vector?
There must be a million ways of doing this! If you want to keep the order: v - c(1,2,3,4,6) sort(c(v,5)) Mick -Original Message- From: jing tang [mailto:[EMAIL PROTECTED] Sent: 22 November 2004 14:44 To: [EMAIL PROTECTED] Subject: [R] How to insert one element into a vector? suppose I want to insert 5 into the vector (1,2,3,4,6) between 4 and 6. thx! __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] How to insert one element into a vector?
michael watson (IAH-C) wrote:
There must be a million ways of doing this!
Actually I'd say there were no ways of doing this, since I dont think
you can actually insert into a vector - you have to create a new vector
that produces the illusion of insertion!
Here's a Q+D function that fails if you try and insert at the start,
or at the end. Its very D.
insert - function(v,e,pos){
return(c(v[1:(pos-1)],e,v[(pos):length(v)]))
}
v=c(1,2,3,4,6)
insert(v,5,5)
[1] 1 2 3 4 5 6
Yay.
insert(v,5,1)
[1] 1 5 1 2 3 4 6
Oops.
Cant be bothered to fix it, the principle is there.
Baz
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Re: [R] How to insert one element into a vector?
?append --- look at the `after' argument. -roger jing tang wrote: suppose I want to insert 5 into the vector (1,2,3,4,6) between 4 and 6. thx! __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html -- Roger D. Peng http://www.biostat.jhsph.edu/~rpeng/ __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] How to insert one element into a vector?
On Monday 22 November 2004 09:19, Barry Rowlingson wrote:
michael watson (IAH-C) wrote:
There must be a million ways of doing this!
Actually I'd say there were no ways of doing this, since I dont
think you can actually insert into a vector - you have to create a
new vector that produces the illusion of insertion!
Here's a Q+D function that fails if you try and insert at the
start, or at the end. Its very D.
insert - function(v,e,pos){
return(c(v[1:(pos-1)],e,v[(pos):length(v)]))
}
Pretty much what 'append' does.
Deepayan
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Re: [R] How to insert one element into a vector?
Barry Rowlingson [EMAIL PROTECTED] writes:
michael watson (IAH-C) wrote:
There must be a million ways of doing this!
Actually I'd say there were no ways of doing this, since I dont
think you can actually insert into a vector - you have to create a new
vector that produces the illusion of insertion!
Here's a Q+D function that fails if you try and insert at the start,
or at the end. Its very D.
insert - function(v,e,pos){
return(c(v[1:(pos-1)],e,v[(pos):length(v)]))
}
This is actually an exercise in a certain introductory book on R, with
the intention of having the student do the obvious c(v[1:4],5,v[5:5])
style computation and maybe think a little about the edge effects. I
only recently saw the somewhat unfortunately named append() function,
which has been in S/R ever since the blue book...:
append(v,5,4)
[1] 1 2 3 4 5 6
--
O__ Peter Dalgaard Blegdamsvej 3
c/ /'_ --- Dept. of Biostatistics 2200 Cph. N
(*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918
~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907
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Re: [R] How to insert one element into a vector?
Deepayan Sarkar wrote: Pretty much what 'append' does. A shame then, that help.search(insert) doesn't find 'append'! I cant think why anyone looking for a way of _inserting_ a value in the middle of a vector would think of looking at append! Python has separate insert and append methods for vectors. x=[1,2,3,4,6] x.insert(4,5) x [1, 2, 3, 4, 5, 6] x.append(99) x [1, 2, 3, 4, 5, 6, 99] Barry __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] How to insert one element into a vector?
On Mon, 22 Nov 2004, Barry Rowlingson wrote: Deepayan Sarkar wrote: Pretty much what 'append' does. A shame then, that help.search(insert) doesn't find 'append'! I cant think why anyone looking for a way of _inserting_ a value in the middle of a vector would think of looking at append! Yes, this should be fixed. Python has separate insert and append methods for vectors. I don't think this is a good idea unless there are efficiency issues. You could always define one: the definition is fairly simple. insert-append -thomas __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
