Displaying 20 results from an estimated 11000 matches similar to: "Should slot<-() alter its first argument?"
2010 Nov 12
1
SEXPs and slots
Hello,
I've created this class:
setClass("example",
representation (
size = "numeric",
id = "character"
)
)
Suppose I create a new instance of this class:
> x <- new("example", 4, "id_value")
This creates an S4 object with two slots. Am I correct in thinking that
slots are "filled" by SEXPs?
2009 Oct 13
1
for loop over S4
Hello,
Consider this :
> setClass("track", representation(x="numeric", y="numeric"))
[1] "track"
> o <- new( "track", x = 1, y = 2 )
> for( i in o ){
+ cat( "hello\n")
+ }
Error: invalid type/length (S4/1) in vector allocation
This happens at those lines of do_for:
n = LENGTH(val);
PROTECT_WITH_INDEX(v =
2009 Jun 23
1
implementing Maximum Likelihood with distrMod when only the PDF is known
Dear R users and Dear authors of the distr package and sequels
I am trying to use the (very nice) package distrMod as I want to
implement maximum likelihood (ML) fit of some univariate data for which
I have derived a theoretical continuous density (pdf). As it is a
parametric density, I guess that I should implement myself a new
distribution of class AbscontDistributions (as stated in the pdf
2007 Dec 13
1
S4 class extending data.frame?
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
I would like to build an S4 class that extends
a data frame, but includes several more slots.
Here's an example using integer as the base
class instead:
setClass("c1",representation(comment="character"),contains="integer")
z1 = new("c1",55,comment="hello")
z1
z1+10
z1[1]
z1 at comment
-- in
2004 Jul 06
1
questions about setMethod("Arith", ...)
Hi,
we have some questions concerning the definition of new arithmetic methods.
In our package "distr" (on CRAN) we define some new arithmetic methods
for "+", "-", "*", "/".
After loading "distr" the corresponding arithmetic methods work. Now, if
we define a new
class and also a new method for one of the arithmetic methods
2016 Aug 05
2
Extra copies of objects in environments when using $ operator?
My understanding is that R will not make copies of lists if there is
only one reference to the object. However, I've encountered a case
where R does make copies, even though (I think) there should be only
one reference to the object. I hope that someone could shed some light
on why this is happening.
I'll start with a simple example. Below, x is a list with one element,
and changing that
2016 May 20
2
identical on closures
I'm confused by this:
> identical(function() {}, function() {})
[1] FALSE
Yet, after loading the Matrix package (which redefines det), the
following is checked (in library.checkConflicts):
> identical(get("det", baseenv()), get("det", asNamespace("Matrix")),
ignore.environment=T)
[1] TRUE
I've looked at the code in identical.c and for closures it
2019 Jul 17
2
ALTREP wrappers and factors
Hello,
I?m experimenting with ALTREP and was wondering if there is a preferred way to create an ALTREP wrapper vector without using .Internal(wrap_meta(?)), which R CMD check doesn?t like since it uses an .Internal() function.
I was trying to create a factor that used an ALTREP integer, but attempting to set the class and levels attributes always ended up duplicating and materializing the
2018 Mar 18
3
`@<-` modify its argument when slot is externalptr
Dear all,
I am confused about the inconsistent behaviors of `@<-` operator when
used in different ways. Consider the following example:
library(inline)
# Function to generate an externalptr object with random address
new_extptr <- cfunction(c(), '
SEXP val = PROTECT(ScalarLogical(1));
SEXP out = PROTECT(R_MakeExternalPtr(&val, R_NilValue, val));
UNPROTECT(2);
2011 Nov 24
1
Confused about NAMED
Hi,
I expected NAMED to be 1 in all these three cases. It is for one of them,
but not the other two?
> R --vanilla
R version 2.14.0 (2011-10-31)
Platform: i386-pc-mingw32/i386 (32-bit)
> x = 1L
> .Internal(inspect(x)) # why NAM(2)? expected NAM(1)
@2514aa0 13 INTSXP g0c1 [NAM(2)] (len=1, tl=0) 1
> y = 1:10
> .Internal(inspect(y)) # NAM(1) as expected but why different to x?
2019 May 16
3
ALTREP: Bug reports
Hello,
I have encountered two bugs when using ALTREP APIs.
1. STDVEC_DATAPTR
>From RInternal.h file it has a comment:
/* ALTREP support */
> void *(STDVEC_DATAPTR)(SEXP x);
However, this comment might not be true, the easiest way to verify it is to
define a C++ function:
void C_testFunc(SEXP a)
> {
> STDVEC_DATAPTR(a);
> }
and call it in R via
> a=1:10
> >
2020 Jan 09
6
Get memory address of an R data frame
Hello,
I would like for my C function to be able to manipulate some values stored in an R data frame.
To achieve this, a need the (real) memory address where the R data frame stores its data (hopefully in a contiguous way). Then, from R, I call the C function and passing this memory address as a parameter.
The question: how can we get the memory address of the R data frame?
Thank you!
L.
2011 Sep 07
1
Very slow assignments
I'm creating an object of a S4 class that has two slots: ListExamples, which
is a list, and idx, which is an integer (as the code below).
Then, I read a data.frame file with 10000 (ten thousands) of lines and 10
columns, do some pre-processing and, basically, I store each line as an
element of a list in the slot ListExamples of the S4 object. However, any
kind of assignment operation (<-)
2019 May 16
3
ALTREP: Bug reports
Hello Luke and Gabriel,
Thank you very much for your quick responses. The explanation of STDVEC is
very helpful and I appreciate it! For the wrapper, I have a few new
questions.
1. Like Luke said a mutable object is not possible. However, I noticed that
there is one extra argument *deep* in the function duplicate. I've googled
all the available documentation for ALTREP but I did not find
2019 Jan 22
2
Objectsize function visiting every element for alt-rep strings
On Mon, 21 Jan 2019, Martin Maechler wrote:
>>>>>> Travers Ching
>>>>>> on Tue, 15 Jan 2019 12:50:45 -0800 writes:
>
> > I have a toy alt-rep string package that generates
> > randomly seeded strings. example: library(altstringisode)
> > x <- altrandomStrings(1e8) head(x) [1]
> >
2018 Apr 29
2
Result of 'seq' doesn't use compact internal representation
> .Internal(inspect(1:10))
@300e4e8 13 INTSXP g0c0 [NAM(3)] 1 : 10 (compact)
> .Internal(inspect(seq(1,10)))
@3b6e1f8 13 INTSXP g0c4 [] (len=10, tl=0) 1,2,3,4,5,...
> system.time(1:1e7)
user system elapsed
0 0 0
> system.time(seq(1,1e7))
user system elapsed
0.05 0.00 0.04
It seems that result of function 'seq' doesn't use compact
2019 Jan 15
4
Objectsize function visiting every element for alt-rep strings
I have a toy alt-rep string package that generates randomly seeded strings.
example:
library(altstringisode)
x <- altrandomStrings(1e8)
head(x)
[1] "2PN0bdwPY7CA8M06zVKEkhHgZVgtV1" "5PN2qmWqBlQ9wQj99nsQzldVI5ZuGX" ... etc
object.size(1e8)
Object.size will call the set_altstring_Elt_method for every single
element, materializing (slowly) every element of the vector. This
2010 Nov 15
1
SEXP and slots
Hello,
Since people have whisperred about Rcpp, I'd like to play too.
> On 11/15/2010 07:45 AM, Patrick Leyshock wrote:
>> Very helpful, thank you.
>>
>> A couple other questions, please:
>>
>> 1. I've got a function written in C, named "my_c_function". In my R
>> code I call this function, passing to it an INTSXP and a STRSXP,
>>
2013 Aug 18
1
How does R_UnboundValue and removing variables work?
Reading "R Internals" made me believe that R_UnboundValue was a placeholder
that would be skipped over in variable lookup. viz. the section of R
Internals "Hash tables" says "items are not actually deleted but have their
value set to R_UnboundValue.", which seems to align with what I read in
envir.c.
So, I reasoned, if I have a function that returns R_UnboundValue,
2010 May 14
1
The parsing of '{' and a function that equal to '{'
Hello All,
I tried the sample code from the help. Although '{' is assigned to
'do', the call syntaxes for 'do' and '{' are not the same ('do' has
','s, but '{' has line breaks). I guess there is a difference in
parsing the code block of 'do' and the code block of '{'. Could you
please let me know some internal details so that