Martin Morgan wrote:
[...]
## Attempt two -- initialize
setClass(Element,
representation=representation(conn=file))
setMethod(initialize, Element, function(.Object, ..., conn=file()) {
callNextMethod(.Object, ..., conn=conn)
})
new(Element)
## oops, connection created but not
Barry Rowlingson wrote:
Would something like
q()
Save workspace image (/home/me/workspace/.RData)? [y/n/c]:
be useful to anyone else? Just thought I'd ask before I dive into
internals or wrap the q function for myself.
yes, it would be very useful to me.
vQ
Mathieu Ribatet wrote:
I guess that having something like this
q()
Save workspace image (/home/me/workspace/.RData)? [y/n/c/e]:
where e means Editing the path should be clear enought, isn't it?
good idea; maybe 'o' for 'other path'; or 'a' for 'alternative path';
or 'd' for
the post 13613 has been classified as featuresfaq and annotated with
As documented in the Warning section!. however, the bug has actually
been fixed.
may i kindly suggest that the annotation be changed to a more
appropriate note?
regards,
vQ
__
William Dunlap wrote:
One of our R users here just showed me the following problem while
investigating the return value of a while loop. I added some
information
on a similar bug in for loops. I think he was using 2.9.0
but I see the same problem on today's development version of 2.10.0
Stavros Macrakis wrote:
In R 2.8.0 on Windows (tested both under ESS and under R Console in case
there was an I/O issue)
There is a bug in printing val - matrix(list(NA_complex_,NA_complex_),1).
dput(val)
structure(list(NA_complex_, NA_complex_), .Dim = 1:2)
print(val)
Wacek Kusnierczyk wrote:
a simplified example may help to get a clear picture:
i = 1; y = 1:3;
(while(TRUE) {
y[i] = 0
if (i == 2) break
i = i + 1
y })
# 0 0 3
i = 1; y = 1:3;
(while(TRUE) {
y[i] = 0
if (i == 2) break
William Dunlap wrote:
help('while') says:
Usage:
for(var in seq) expr
while(cond) expr
repeat expr
break
next
Value:
'for', 'while' and 'repeat' return the value of the last
expression evaluated (or 'NULL' if none was), invisibly. 'for'
sets
William Dunlap wrote:
It looks like the 'seq' variable to 'for' can be altered from
within the loop, leading to incorrect answers. E.g., in
the following I'd expect 'sum' to be 1+2=3, but R 2.10.0
(svn 48686) gives 44.5.
x = c(1,2); sum = 0; for (i in x) { x[i+1] = i + 42.5; sum = sum
Stavros Macrakis wrote:
'1:3' %in% data.frame(a=2:4,b=1:3) # TRUE
utterly weird. so what would x have to be so that
x %in% data.frame('a')
# TRUE
hint:
'1' %in% data.frame(1)
# TRUE
vQ
__
R-devel@r-project.org mailing
William Dunlap wrote:
%in% is a thin wrapper on a call to match(). match() is
not a generic function (and is not documented to be one),
so it treats data.frames as lists, as their underlying
representation is a list of columns. match is documented
to convert lists to character and to then
Barry Rowlingson wrote:
[...]
I suspect it's using 'deparse()' to get the character representation.
This function is mentioned in ?as.character, but as.character.default
disappears into the infernal .Internal and I don't have time to chase
source code - it's sunny outside!
on the side,
Martin Maechler wrote:
PS == Petr Savicky savi...@cs.cas.cz
on Sun, 31 May 2009 10:29:41 +0200 writes:
[]
PS I appreciate the current version, which contains static
PS const char* dropTrailing0(char *s, char cdec) ...
PS mkChar(dropTrailing0((char
Martin Maechler wrote:
Hi Waclav (and other interested parties),
I have committed my working version of src/main/coerce.c
so you can prepare your patch against that.
some further investigation and reflections on the code in StringFromReal
(henceforth SFR), src/main/coerce.c:315 (as in the
Martin Maechler wrote:
[...]
vQ the first question is, why does ER return the string as const? it
vQ appears that the returned pointer provides the address of a buffer
used
vQ internally in ER, which is allocated *statically*. that is, each call
vQ to ER operates on the
src/main/character.c:435-438 (do_strsplit) contains the following code:
for (i = 0; i tlen; i++)
if (getCharCE(STRING_ELT(tok, 0)) == CE_UTF8) use_UTF8 = TRUE;
for (i = 0; i len; i++)
if (getCharCE(STRING_ELT(x, 0)) == CE_UTF8) use_UTF8 = TRUE;
since both loops iterate
Petr Savicky wrote:
On Fri, May 29, 2009 at 03:53:02PM +0200, Martin Maechler wrote:
my version of *using* the function was
1 SEXP attribute_hidden StringFromReal(double x, int *warn)
2 {
3 int w, d, e;
4 formatReal(x, 1, w, d, e, 0);
5 if (ISNA(x)) return NA_STRING;
6 else
Martin Maechler wrote:
[...]
vQ you return s, which should be the same pointer value (given the actual
vQ code that does not modify the local variable s) with the same
pointed-to
vQ string value (given the signature of the function).
vQ was perhaps
vQ char
Martin Maechler wrote:
Hi Waclav (and other interested parties),
I have committed my working version of src/main/coerce.c
so you can prepare your patch against that.
Hi Martin,
One quick reaction (which does not resolve my original complaint): you
can have p non-const, and cast s to
Stavros Macrakis wrote:
This is another example of the general preference of the designers of R for
convenience over consistency.
In my opinion, this is a design flaw even for non-programmers, because I
find that inconsistencies make the system harder to learn. Yes, the naive
user may
(diverted to r-devel, a source code patch attached)
Wacek Kusnierczyk wrote:
Allan Engelhardt wrote:
Immaterial, yes, but it is always good to test :) and your solution
*is* faster and it is even faster if you can assume byte strings:
:)
indeed; though if the speed is immaterial
William Dunlap wrote:
Would your patched code affect the following
use of regexpr's output as input to substr, to
pull out the matched text from the string?
x-c(ooo,good food,bad)
r-regexpr(o+, x)
substring(x,r,attr(r,match.length)+r-1)
[1] ooo oo
no; same output
Wacek Kusnierczyk wrote:
William Dunlap wrote:
Would your patched code affect the following
use of regexpr's output as input to substr, to
pull out the matched text from the string?
x-c(ooo,good food,bad)
r-regexpr(o+, x)
substring(x,r,attr(r,match.length)+r-1)
[1] ooo
sec. 1.1 says:
both types of node structure have as their first three fields a 32-bit
sxpinfo header and then three pointers [...]
that's *four* fields, as seen in src/include/Rinternals.h:208+:
#define SEXPREC_HEADER \
struct sxpinfo_struct sxpinfo; \
struct SEXPREC *attrib; \
Martin Maechler wrote:
I have very slightly modified the changes (to get rid of -Wall
warnings) and also exported the function as Rf_dropTrailing0(),
and tested the result with 'make check-all' .
As the change seems reasonable and consequent, and as
it seems not to produce any problems in
Kynn Jones wrote:
Hi. I'm pretty new to R, but I've been programming in other languages for
some time. I have a couple of questions regarding programming with function
objects.
1. Is there a way for a function to refer generically to all its actual
arguments as a list? I'm thinking of
Wacek Kusnierczyk wrote:
Kynn Jones wrote:
In general, I'm looking for all the information I can find on the subject of
dynamic function definition (i.e. using code to automate the definition of
functions at runtime). I'm most interested in introspection facilities and
dynamic code
Wacek Kusnierczyk wrote:
Wacek Kusnierczyk wrote:
Kynn Jones wrote:
In general, I'm looking for all the information I can find on the subject of
dynamic function definition (i.e. using code to automate the definition of
functions at runtime). I'm most interested
Ben Bolker wrote:
It's my vague impression that View() is workable on Windows and maybe
on MacOS, but on Ubuntu Linux 9.04 (intrepid) it seems completely
unstable. I can reliably crash R by trying to look at a very small,
simple data frame ...
on my 8.04, r is reliable at crashing
Peter Dalgaard wrote:
Will Gray wrote:
Perhaps this is the intended behavior, but I discovered that unsplit
throws an error when it tries to set rownames of a variable that has
no dimension. This occurs when unsplit is passed a list of
data.frames that have only a single column.
An
Romain Francois wrote:
txt - grep( '^tr.*td align=right.*a', readLines( url ), value =
TRUE )
rx - '^.*?a href=(.*?)(.*?)/a.*td(.*?)/td.*$'
out - data.frame(
url = gsub( rx, \\1, txt ),
group = gsub( rx, \\2, txt ),
description = gsub( rx, \\3, txt ),
Romain Francois wrote:
strapply in package gsubfn brings elegance here:
txt - 'foobar/foo'
rx - (.*?)(.*?)/(.*?)
strapply( txt, rx, c , perl = T )
[[1]]
[1] foo bar foo
sure, but this does not, in any way, make it less strange that gsub is
not vectorized.
Too bad you have to pay
hadley wickham wrote:
On Fri, May 8, 2009 at 10:11 AM, Romain Francois
romain.franc...@dbmail.com wrote:
strapply in package gsubfn brings elegance here:
txt - 'foobar/foo'
rx - (.*?)(.*?)/(.*?)
strapply( txt, rx, c , perl = T )
[[1]]
[1] foo bar foo
Too bad you have
Stavros Macrakis wrote:
These look like important improvements. As a relative newcomer to the R
community, I'm not sure I understand what the procedures are for such
changes.
In particular, does the fact that the changes were committed to R-devel mean
that the changes have already been
Gabor Grothendieck wrote:
On Fri, Apr 24, 2009 at 6:45 AM, maech...@stat.math.ethz.ch wrote:
Yes, the documentation will also have to be amended, but apart
from that, would people see a big problem with the 8192 limit
which now is suddenly of greater importance
{{as I said all along;
maech...@stat.math.ethz.ch wrote:
vQ sprintf has a documented limit on strings included in the output
using the
vQ format '%s'. It appears that there is a limit on the length of
strings included
vQ with, e.g., the format '%d' beyond which surprising things happen
(output
maech...@stat.math.ethz.ch wrote:
vQ sprintf has a documented limit on strings included in the output
using the
vQ format '%s'. It appears that there is a limit on the length of
strings included
vQ with, e.g., the format '%d' beyond which surprising things happen
(output
sprintf has a limit on the length of a string produced with a '%s'
specification:
nchar(sprintf('%1s', ''))
# 8191
nchar(sprintf('%*s', 1, ''))
# 8191
This is sort of documented in ?sprintf:
There is a limit of 8192 bytes on elements of 'fmt' and also on
strings
Peter Dalgaard wrote:
Wacek Kusnierczyk wrote:
Stavros Macrakis wrote:
`-`
Error: object - not found
that's weird!
Why???
partly because it was april fools.
but more seriously, it's because one could assume that in any syntactic
expression with an operator involved
Wacek Kusnierczyk wrote:
and btw. the following is also weird:
quote(a=1)
# 1
not because '=' works as named argument specifier (so that the result
would be something like `=`(a, 1)),
i meant to write: not because '=' does not work as an assignment
operator (or otherwise
Stavros Macrakis wrote:
On Wed, Apr 1, 2009 at 5:11 PM, Wacek Kusnierczyk
waclaw.marcin.kusnierc...@idi.ntnu.no wrote:
Stavros Macrakis wrote:
...
i think this concords with the documentation in the sense that in an
assignment a string can work as a name. note that
`foo bar` = 1
Thomas Lumley wrote:
The explanation is that quote() is a primitive function and that the
argument matching rules do not apply to primitives. That section of
the R Language definition should say that primitives are excluded; it
is documented in ?.Primitive.
thanks. indeed, the
Martin Maechler wrote:
WK i attach the patch post for reference. note that you need to fix all
of
WK the functions in duplicated.R that share the buggy code. (yes, this
was
WK another thread; i submitted a bug report, and then sent a follow-up
WK post with a patch).
Martin Maechler wrote:
Your patch is basically only affecting the default
method = pearson. For (most) other cases, 'y = NULL' would
still remain *the* way to save computations, unless we'd start
to use an R-level equivalent [which I think does not exist] of
your C trick (DATAPTR(x) ==
Martin Maechler wrote:
Using 'bug' (without any qualifying ? or possible ..)
in the subject line is still a bit unfriendly...
is suggesting that a poster includes 'excel bug' in the subject line [1]
friendly??
vQ
[1] https://stat.ethz.ch/pipermail/r-help/2009-March/190119.html
Stavros Macrakis wrote:
The documentation for assignment says:
In all the assignment operator expressions, 'x' can be a name or
an expression defining a part of an object to be replaced (e.g.,
'z[[1]]'). A syntactic name does not need to be quoted, though it
can be
Martin Maechler wrote:
(...)
WK which shows that raw won't coerce to the four first types in the
WK 'hierarchy' (excluding NULL), but it will to character, list, and
WK expression.
WK suggestion: improve the documentation, or adapt the implementation
to
WK a more
Martin Maechler wrote:
WK what the documentation *fails* to tell you is that the parameter
WK 'incomparables' is defunct
No, not defunct, but the contrary of it,
not yet implemented !
that's my bad english, again. sorry.
WK # data as above, or any data frame
WK
Stavros Macrakis wrote:
The documentation of as.data.frame is not explicit about how it generates
column names for the simple vector case, but it seems to use the character
form of the quoted argument, e.g.
names(as.data.frame(1:3))
[1] 1:3
But there is a strange case:
(), incomparables=NA)
# error: argument 'incomparables != FALSE' is not used (yet)
regards,
vQ
waclaw.marcin.kusnierc...@idi.ntnu.no wrote:
Full_Name: Wacek Kusnierczyk
Version: 2.8.0 and 2.10.0 r48242
OS: Ubuntu 8.04 Linux 32 bit
Submission from: (NULL) (129.241.110.161)
In the following code
make
make check
and now
duplicated(data.frame(), incomparables=NA)
# error: argument 'incomparables != FALSE' is not used (yet)
regards,
vQ
waclaw.marcin.kusnierc...@idi.ntnu.no wrote:
Full_Name: Wacek Kusnierczyk
Version: 2.8.0 and 2.10.0 r48242
OS: Ubuntu 8.04 Linux 32 bit
Romain Francois wrote:
Wacek Kusnierczyk wrote:
redirected to r-devel, because there are implementational details of
[.data.frame discussed here. spoiler: at the bottom there is a fairly
interesting performance result.
Romain Francois wrote:
Hi,
This is a bug I think. [.data.frame
redirected to r-devel, because there are implementational details of
[.data.frame discussed here. spoiler: at the bottom there is a fairly
interesting performance result.
Romain Francois wrote:
Hi,
This is a bug I think. [.data.frame treats its arguments differently
depending on the number
Sklyar, Oleg (London) wrote:
typo as simple as %S instead of %s segfaults R devel:
not exactly:
sprintf('%S', 'aa')
# error: unrecognised format at end of string
without a segfault. but with another format specifier behind, it will
cause a segfault.
interestingly, here's again
William Dunlap wrote:
Doesn't Fortran still require that the arguments to
a function not alias each other (in whole or in part)?
what do you mean? the following works pretty fine:
echo '
program foo
implicit none
integer, target :: a = 1
integer,
somewhat related to a previous discussion [1] on how 'names-' would
sometimes modify its argument in place, and sometimes produce a modified
copy without changing the original, here's another example of how it
becomes visible to the user when r makes or doesn't make a copy of an
object:
x =
Martin Maechler wrote:
more verbously, all NULL objects in R are identical, or as the
help page says, there's only ``*The* NULL Object'' in R,
i.e., NULL cannot get any attributes.
WK yes, but that's not the issue. the issue is that names(x)- seems to
WK try
--
---
Wacek Kusnierczyk, MD PhD
Email: w...@idi.ntnu.no
Phone: +47 73591875, +47 72574609
Department of Computer and Information Science (IDI)
Faculty of Information Technology, Mathematics and Electrical Engineering (IME)
Norwegian University of Science and Technology (NTNU)
Sem
(this post suggests a patch to the sources, so i allow myself to divert
it to r-devel)
Bert Gunter wrote:
x a numeric vector, matrix or data frame.
y NULL (default) or a vector, matrix or data frame with compatible
dimensions to x. The default is equivalent to y = x (but more efficient).
there seems to be something wrong with r's regexing. consider the
following example:
gregexpr('a*|b', 'ab')
# positions: 1 2
# lengths: 1 1
gsub('a*|b', '.', 'ab')
# ..
where the pattern matches any number of 'a's or one b, and replaces the
match with a dot, globally. the
strangely enough, the way r handles the same sequence of expressions on
different occasions varies:
# fresh session 1
e = simpleError('foo')
sprintf('%s', e)
# segfault: address 0x202, cause memory not mapped
# ^c
sprintf('%s', e)
# error in sprintf(%s, e) :
Wacek Kusnierczyk wrote:
interestingly,
c(1, as.raw(1))
# error: type 'raw' is unimplemented in 'RealAnswer'
three more comments.
(1)
the above is interesting in the light of what ?c says:
The output type is determined from the highest type of the
components
Petr Savicky wrote:
On Mon, Mar 16, 2009 at 07:39:23PM -0400, Stavros Macrakis wrote:
...
Let's look at the extraordinarily poor behavior I was mentioning. Consider:
nums - (.3 + 2e-16 * c(-2,-1,1,2)); nums
[1] 0.3 0.3 0.3 0.3
Though they all print as .3 with the default precision
Wacek Kusnierczyk wrote:
there's one more curiosity about factors, in particular, ordered factors:
ord - as.ordered(nums); ord
# [1] 0.300 0.3 0.3
0.300
# Levels: 0.300 0.3 0.3 0.300
ord[1
Berwin A Turlach wrote:
'*tmp*' = 0
`*tmp*`
# 0
x = 1
names(x) = 'foo'
`*tmp*`
# error: object *tmp* not found
`*ugly*`
I agree, and I am a bit flabbergasted. I had not expected that
something like this would happen and I am indeed not aware of anything
in the documentation
somewhat one the side,
l = list(1)
l[[2]]
# error, index out of bounds
l[2][[1]]
# NULL
that is, we can't extract from l any element at an index exceeding the
list's length (if we could, it would have been NULL or some sort of
_NA_list), but we can extract a sublist at
Thomas Lumley wrote:
Wacek,
In this case I think the *tmp* dates from the days before backticks,
when it was not a legal name (it still isn't) and it was much, much
harder to use illegal names, so the collision issue really didn't exist.
thanks for the explanation.
You're right about the
Duncan Murdoch wrote:
On 3/16/2009 9:36 AM, Daniel Murphy wrote:
Hello:I am trying to match the value 0.3 in the sequence seq(.2,.3).
I get
0.3 %in% seq(from=.2,to=.3)
[1] FALSE
Yet
0.3 %in% c(.2,.3)
[1] TRUE
For arbitrary sequences, this invisible .3 has been problematic.
What is
the
Petr Savicky wrote:
On Mon, Mar 16, 2009 at 06:36:53AM -0700, Daniel Murphy wrote:
Hello:I am trying to match the value 0.3 in the sequence seq(.2,.3). I get
0.3 %in% seq(from=.2,to=.3)
[1] FALSE
As others already pointed out, you should use
Berwin A Turlach wrote:
Obviously, assuming that R really executes
*tmp* - x
x - names-('*tmp*', value=c(a,b))
under the hood, in the C code, then *tmp* does not end up in the symbol
table and does not persist beyond the execution of
names(x) - c(a,b)
to prove that
Stavros Macrakis wrote:
Well, that's one issue. But another is that there should be a
specification addressed to users, who should not have to understand
internals.
this should really be taken seriously.
vQ
__
R-devel@r-project.org mailing
Berwin A Turlach wrote:
On Sat, 14 Mar 2009 07:22:34 +0100
Wacek Kusnierczyk waclaw.marcin.kusnierc...@idi.ntnu.no wrote:
[...]
Well, I don't see any new object created in my workspace after
x - 4
names(x) - foo
Do you?
of course not. that's why i'd say the two
Berwin A Turlach wrote:
foo = function(arg) arg$foo = foo
e = new.env()
foo(e)
e$foo
are you sure this is pass by value?
But that is what environments are for, aren't they?
might be.
And it is
documented behaviour.
sure!
Read section 2.1.10
Berwin A Turlach wrote:
sure!
Glad to see that we agree on this.
owe you a beer.
Read section 2.1.10 (Environments) in the R
Language Definition,
haven't objected to that. i object to your 'r uses pass by value',
which is only partially correct.
Well, I
William Dunlap wrote:
Would it make anyone any happier if the manual said
that the replacement functions should not be called
in the form
xNew - `func-` (xOld, value)
and should only be used as
func(xToBeChanged) - value
surely better than guesswork.
?
The explanation
Tony Plate wrote:
Wacek Kusnierczyk wrote:
[snip]
i just can't get it why the manual does not manifestly explain what
'names-' does, and leaves you doing the guesswork you suggest.
I'm having trouble understanding the point of this discussion.
Someone is calling a replacement function
Tony Plate wrote:
Wacek Kusnierczyk wrote:
Tony Plate wrote:
Is there anything incorrect or missing in the help page for normal
usage of the replacement function for 'names'? (i.e., when used in an
expression like 'names(x) - ...')
what is missing here in the first place
Berwin A Turlach wrote:
On Wed, 11 Mar 2009 20:31:18 +0100
Wacek Kusnierczyk waclaw.marcin.kusnierc...@idi.ntnu.no wrote:
Simon Urbanek wrote:
On Mar 11, 2009, at 10:52 , Simon Urbanek wrote:
Wacek,
Peter gave you a full answer explaining it very well. If you really
Berwin A Turlach wrote:
On Wed, 11 Mar 2009 20:29:14 +0100
Wacek Kusnierczyk waclaw.marcin.kusnierc...@idi.ntnu.no wrote:
Simon Urbanek wrote:
Wacek,
Peter gave you a full answer explaining it very well. If you really
want to be able to trace each instance yourself, you have
Berwin A Turlach wrote:
Whoever said that must have been at that moment not as precise as he or
she could have been. Also, R does not behave according to what people
say on this list (which is good, because some times people they wrong
things on this list) but according to how it is
Wacek Kusnierczyk wrote:
is precisely why i'd think that the prefix 'names-' should never do
destructive modifications, because that's what x = 'names-'(x, 'foo'),
and thus also names(x) = 'foo', is for.
to make the point differently, i'd expect the following two to be
equivalent:
x
Berwin A Turlach wrote:
On Thu, 12 Mar 2009 10:53:19 +0100
Wacek Kusnierczyk waclaw.marcin.kusnierc...@idi.ntnu.no wrote:
well, ?'names-' says:
Value:
For 'names-', the updated object.
which is only partially correct, in that the value will sometimes be
an updated *copy
Wacek Kusnierczyk wrote:
Berwin A Turlach wrote:
This is similar to the discussion what value i should have in the
following C snippet:
i = 0;
i += i++;
in fact, your example is useless because the result here is clearly
specified by the semantics (as far as i
l...@stat.uiowa.edu wrote:
Thanks to Stavros for the report. This should now be fixed in R-devel.
indeed, though i find some of the error messages strange:
(function(a=a) -a)()
# Error in (function(a = a) -a)() :
# element 1 is empty;
# the part of the args list of '-' being
Simon Urbanek wrote:
On Mar 11, 2009, at 10:52 , Simon Urbanek wrote:
Wacek,
Peter gave you a full answer explaining it very well. If you really
want to be able to trace each instance yourself, you have to learn
far more about R internals than you apparently know (and Peter hinted
at
Berwin A Turlach wrote:
On Thu, 12 Mar 2009 15:21:50 +0100
Wacek Kusnierczyk waclaw.marcin.kusnierc...@idi.ntnu.no wrote:
seems to suggest? is not the purpose of documentation to clearly,
ideally beyond any doubt, specify what is to be specified?
The R Language Definition manual
Simon Urbanek wrote:
On Mar 12, 2009, at 11:12 , Wacek Kusnierczyk wrote:
Simon Urbanek wrote:
On Mar 11, 2009, at 10:52 , Simon Urbanek wrote:
Wacek,
Peter gave you a full answer explaining it very well. If you really
want to be able to trace each instance yourself, you have to learn
G. Jay Kerns wrote:
Wacek Kusnierczyk wrote:
I am prompted to imagine someone pointing out to the volunteers of the
International Red Cross - on the field of a natural disaster, no less
- that their uniforms are not an acceptably consistent shade of
pink... or that the screws
Simon Urbanek wrote:
Wacek,
Peter gave you a full answer explaining it very well. If you really
want to be able to trace each instance yourself, you have to learn far
more about R internals than you apparently know (and Peter hinted at
that). Internally x=1 an x=c(1) are slightly different
Simon Urbanek wrote:
On Mar 11, 2009, at 10:52 , Simon Urbanek wrote:
Wacek,
Peter gave you a full answer explaining it very well. If you really
want to be able to trace each instance yourself, you have to learn
far more about R internals than you apparently know (and Peter hinted
at
playing with 'names-', i observed the following:
x = 1
names(x)
# NULL
'names-'(x, 'foo')
# c(foo=1)
names(x)
# NULL
where 'names-' has a functional flavour (does not change x), but:
x = 1:2
names(x)
# NULL
'names-'(x, 'foo')
# c(foo=1, 2)
Peter Dalgaard wrote:
Wacek Kusnierczyk wrote:
playing with 'names-', i observed the following:
x = 1
names(x)
# NULL
'names-'(x, 'foo')
# c(foo=1)
names(x)
# NULL
where 'names-' has a functional flavour (does not change x), but:
x = 1:2
Stavros Macrakis wrote:
(B) you cannot (easily) predict whether or not x will be modified
destructively
that's fine, thanks, but i must be terribly stupid as i do not see how
this explains the examples above. where is the x used by something else
in the first example, so that
Peter Dalgaard wrote:
(*) unless you mess with match.call() or substitute() and the like. But
that's a different story.
different or not, it is a story that happens quite often -- too often,
perhaps -- to the degree that one may be tempted to say that the
semantics of argument passing in r
Duncan Murdoch wrote:
On 10/03/2009 4:35 PM, michael_ka...@earthlink.net wrote:
Full_Name: Michael Aaron Karsh
Version: 2.8.0
OS: Windows XP
Submission from: (NULL) (164.67.71.215)
When I try to say if (method==f), where f is a function, it says that
the
comparison is only possible for
(*) unless you mess with match.call() or substitute() and the like. But
that's a different story.
--
---
Wacek Kusnierczyk, MD PhD
Email: w...@idi.ntnu.no
Phone: +47 73591875, +47 72574609
Department of Computer
Stavros Macrakis wrote:
Tested in: R version 2.8.1 (2008-12-22) / Windows
Recursive default argument references normally give nice clear errors.
In the first set of examples, you get the error:
Error in ... :
promise already under evaluation: recursive default argument
reference or
ivo...@gmail.com wrote:
Gentlemen---these are all very clever workarounds, but please forgive me
for voicing my own opinion: IMHO, returning multiple values in a
statistical language should really be part of the language itself. there
should be a standard syntax of some sort, whatever it
mark.braving...@csiro.au wrote:
The syntax for returning multiple arguments does not strike me as
particularly appealing. would it not possible to allow syntax like:
f= function() { return( rnorm(10), rnorm(20) ) }
(a,d$b) = f()
FWIW, my own solution is to define a
ivo...@gmail.com wrote:
Gentlemen---these are all very clever workarounds,
hacks around the lack of a feature
but please forgive me for voicing my own opinion: IMHO, returning
multiple values in a statistical language should really be part of the
language itself.
returning multiple values
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