This seems very similar to the data.table package.
The 'by' argument splits the data.table by that value then executes the j
expression within each subset. The package documentation talks about
'subset' and 'with' in some detail. See ?"[.data.table".
dt = data.table(x=1:20, y=rep(1:4,each=5)
I see the same problem. The wiki link on the R homepage doesn't seem to
respond.
A search of r-devel for subjects containing "wiki" finds this seemingly
unanswered recent post.
Is it known?
-Matthew
"Ben Bolker" wrote in message
news:4b44b12a.60...@ufl.edu...
>
___
A search for "c.factor" returns tons of hits on this topic.
Heres just one of the hits from 2006, when I asked the same question :
http://tolstoy.newcastle.edu.au/R/e2/devel/06/11/1137.html
So it appears to be complicated and there are good reasons.
Since I needed it, I created c.factor in data.
> concat() doesn't get a lot of use
How do you know? Maybe its used a lot but the users had no need to tell you
what they were using. The exact opposite might in fact be the case i.e.
because concat is so good in splus, you just never hear of problems with it
from the users. That might be a v
Looking at shash in unique.c, from R-2.10.1 I'm wondering if it makes sense
to hash the pointer itself rather than the string it points to?
In other words could the SEXP pointer be cast to unsigned int and the usual
scatter be called on that as if it were integer?
shash would look like a sligh
Under the "further resources" section I'd like to suggest the following
addition :
* http://crantastic.org/ lists popular packages according to other users
votes. Consider briefly reviewing the top 30 packages before posting to
r-help since someone may have already released a package that solv
s to you along with the patch. It would
be on 32bit Ubuntu first, and I would need to either buy, rent time on, or
borrow a 64bit machine to be able to then test there, owing to the nature of
the suggestion.
If its "no", "bad idea because..." or "we were already wor
Thanks a lot. Quick and brief responses below...
"Duncan Murdoch" wrote in message
news:4b90f134.6070...@stats.uwo.ca...
> Matthew Dowle wrote:
>> I was hoping for a 'yes', 'no', 'maybe' or 'bad idea because ...'. No
>> response
that no one reads it. We should be thinking of ways to cut it
down to a smaller size instead.
On Fri, Mar 5, 2010 at 5:52 AM, Matthew Dowle
wrote:
> Under the "further resources" section I'd like to suggest the following
> addition :
>
> * http://crantastic.org/ lis
>From copyVector in duplicate.c :
void copyVector(SEXP s, SEXP t)
{
int i, ns, nt;
nt = LENGTH(t);
ns = LENGTH(s);
switch (TYPEOF(s)) {
...
case INTSXP:
for (i = 0; i < ns; i++)
INTEGER(s)[i] = INTEGER(t)[i % nt];
break;
...
could that be replaced with :
c
Is this a thumbs up for memcpy for DUPLICATE_ATOMIC_VECTOR at least ?
If there is further specific testing then let me know, happy to help, but
you seem to have beaten me to it.
Matthew
"Simon Urbanek" wrote in message
news:65d21b93-a737-4a94-bdf4-ad7e90518...@r-project.org...
>
> On Apr 21
src) != INTSXP) error("src must be integer data") ;
for(i=0;i -Original Message-
> From: r-devel-boun...@r-project.org
> [mailto:r-devel-boun...@r-project.org] On Behalf Of Romain Francois
> Sent: Wednesday, April 21, 2010 12:32 PM
> To: Matthew Dowle
> Cc: r-de
Hi,
I'm trying to write a function to return an R vector which points
directly to a contiguous subset of another vector, without taking a
copy. Since SEXPREC is a header followed by the data, rather than the
header plus a pointer to the data, I'm not sure what I'm trying to do is
possible. Is t
Dear R-devel,
REvolution appear to be offering ParallelR only when bundled with their R
Enterprise edition. As such it appears to be non-free and closed source.
http://www.revolution-computing.com/products/parallel-r.php
Since R is GPL and not LGPL, is this a breach of the GPL ?
Below is t
e.
Could someone from the R Foundation or the FSF step in and clarify the
situation please ? If in your opinion it is all fine what people are
doing, why not release R under the LGPL for clarity ?
Regards, Matthew
- Original Message -
From: "David M Smith"
To: "Mat
Dear Danese,
Without prejudice save as to costs
I am the author of the R library "data.table". I released data.table under the
provisions of the General Public License (GPL). This email is to notify
REvolution that we may be in dispute. If we are in dispute then I am entitled
to issue litigat
Hi,
Following previous discussion on this list
(http://tolstoy.newcastle.edu.au/R/devel/05/12/3439.html) I have created a
package as suggested, and uploaded it to CRAN incoming : data.table.tar.gz.
** Your comments and feedback will be very much appreciated. **
>From help(data.table) :
This cl
Hi,
Given factors x and y, c(x,y) does not seem to return a useful result :
> x
[1] a b c d e
Levels: a b c d e
> y
[1] d e f g h
Levels: d e f g h
> c(x,y)
[1] 1 2 3 4 5 1 2 3 4 5
>
Is there a case for a new method c.factor as follows? Does something
similar exist already? Is there a bette
s case, which is why I avoided it in
the solution I posted.
Regards,
Matthew
> -Original Message-
> From: Prof Brian Ripley [mailto:[EMAIL PROTECTED]
> Sent: 14 November 2006 18:23
> To: Marc Schwartz
> Cc: Matthew Dowle; r-devel@r-project.org
> Subject: Re: [Rd] c.fa
> Just for clarification, my interest was only to provide an
> alternative that provided for a more generic approach, at
> least in a narrow application, not that I was advocating it's
> need.
Understood, apologies for falsely implying your advocation.
> I would agree with Prof. Ripley's comm
I noticed that a new feature in R 2.4 is that unlist of a list of factors
already does the operation that I proposed :
> x = factor(letters[1:5])
> y = factor(letters[4:8])
> unlist(list(x,y))
[1] a b c d e d e f g h
Levels: a b c d e f g h
>
Therefore, does it not make sense that c(x,y) shoul
I just noticed that a new feature in R 2.4 is that unlist of a list of
factors
already does the operation that I proposed :
> x = factor(letters[1:5])
> y = factor(letters[4:8])
> unlist(list(x,y))
[1] a b c d e d e f g h
Levels: a b c d e f g h
>
Therefore, does it not make sense that c(x,y) s
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