Displaying 12 results from an estimated 12 matches for "integervector".
2015 Mar 02
1
R-devel does not update the C++ returned variables
...ith compiled code.
|
| When testing that, I've went a step further:
As you may know, int can be 'casted up' to double which is what happens
here. So in what follows you _always_ create a copy from an int vector to a
numeric vector.
For pure int, use eg
Rcpp::cppFunction("IntegerVector doubleThis(IntegeerVector x) { return(2*x); }")
and rename the function names as needed to have two defined concurrently.
Dirk
|
| ##---- now "test":
| require(microbenchmark)
| i <- 1:10
| (mb <- microbenchmark(doubleThis(i), i*2, 2*i, i*2L, 2L*i, i+i, times=2^12))
| ## Ly...
2015 Mar 02
3
R-devel does not update the C++ returned variables
...ms also depends on the size
of the input vector. i + i becomes the winner for longer vectors (e.g. i
<- 1:1e6), but a proper Rcpp version is still approximately twice as fast.
Rcpp::cppFunction("NumericVector doubleThisNum(NumericVector x) {
return(2*x); }")
Rcpp::cppFunction("IntegerVector doubleThisInt(IntegerVector x) {
return(2*x); }")
i <- 1:1e6
mb <- microbenchmark::microbenchmark(doubleThisNum(i), doubleThisInt(i),
i*2, 2*i, i*2L, 2L*i, i+i, times=100)
plot(mb, log="y", notch=TRUE)
> (mb <- microbenchmark(doubleThis(i), i*2, 2*i, i*2L, 2L*i, i+i,...
2018 Sep 21
1
Bias in R's random integers?
On 9/20/18 5:15 PM, Duncan Murdoch wrote:
> On 20/09/2018 6:59 AM, Ralf Stubner wrote:
>> It is difficult to do this in a package, since R does not provide access
>> to the random bits generated by the RNG. Only a float in (0,1) is
>> available via unif_rand().
>
> I believe it is safe to multiply the unif_rand() value by 2^32, and take
> the whole number part as an
2015 Mar 02
0
R-devel does not update the C++ returned variables
...> 2L * i
[1] 2147483642 2147483644 2147483646 NA NA NA
Warning message:
In 2L * i : NAs produced by integer overflow
H.
>
> Rcpp::cppFunction("NumericVector doubleThisNum(NumericVector x) {
> return(2*x); }")
> Rcpp::cppFunction("IntegerVector doubleThisInt(IntegerVector x) {
> return(2*x); }")
> i <- 1:1e6
> mb <- microbenchmark::microbenchmark(doubleThisNum(i), doubleThisInt(i),
> i*2, 2*i, i*2L, 2L*i, i+i, times=100)
> plot(mb, log="y", notch=TRUE)
>
>
>> (mb <- microbenchmark(doubleT...
2015 Mar 02
3
R-devel does not update the C++ returned variables
On 2 March 2015 at 09:09, Duncan Murdoch wrote:
| I generally recommend that people use Rcpp, which hides a lot of the
| details. It will generate your .Call calls for you, and generate the
| C++ code that receives them; you just need to think about the real
| problem, not the interface. It has its own learning curve, but I think
| it is easier than using the low-level code that you need to
2011 Jan 26
2
Dealing with R list objects in C/C++
Hi,
I'd like to construct an R list object in C++, fill it with relevant data, and pass it to an R function which will return a different list object back. I have browsed through all the R manuals, and examples under tests/Embedding, but can't figure out the correct way. Below is my code snippet:
#include <Rinternals.h>
// Rf_initEmbeddedR and other setups already performed
2010 Oct 27
2
must .Call C functions return SEXP?
For using R's .Call interface to C functions, all the examples I've
seen have the C function return type SEXP. Why? What does R actually
do with this return type? What happens if I *don't* return a SEXP?
Reason I ask, is I've written some R code which allocates two long
lists, and then calls a C function with .Call. My C code writes to
those two pre-allocated lists, thus, I
2010 May 17
0
Rcpp 0.8.0 on CRAN
...as released to CRAN today. This release
marks another milestone in the ongoing redesign of the package, and
underlying C++ library.
===== Overview =====
Rcpp is an R package and C++ library that facilitates integration of C++
code in R packages.
The package features a set of C++ classes (Rcpp::IntegerVector,
Rcpp::Function, Rcpp::Environment, ...) that makes it easier to manipulate R
objects of matching types (integer vectors, functions, environments, etc
...).
Rcpp takes advantage of C++ language features such as the explicit
constructor/destructor lifecycle of objects to manage garbage collection
a...
2010 May 17
0
Rcpp 0.8.0 on CRAN
...as released to CRAN today. This release
marks another milestone in the ongoing redesign of the package, and
underlying C++ library.
===== Overview =====
Rcpp is an R package and C++ library that facilitates integration of C++
code in R packages.
The package features a set of C++ classes (Rcpp::IntegerVector,
Rcpp::Function, Rcpp::Environment, ...) that makes it easier to manipulate R
objects of matching types (integer vectors, functions, environments, etc
...).
Rcpp takes advantage of C++ language features such as the explicit
constructor/destructor lifecycle of objects to manage garbage collection
a...
2010 Apr 13
3
Inline Package: void vs return type functions
Dear all,
After having a look at the "inline" package and also going through the
"Rcpp" package which is tighty related to it, it came to me this question:
1) my C/ C++ code has a return type (let say a double[][] or a user define
class)
2) I am working with an extensive library built by someone else and I don't
have the time/knowledge to change it by means of working
2010 Dec 22
0
Rcpp 0.9.0 and RcppClassic 0.9.0
...few key
points are highlighted below. More details are in the NEWS and ChangeLog
files included in the package.
===== Overview =====
Rcpp is an R package and associated C++ library that facilitates integration
of C++ code in R packages.
The package features a complete set of C++ classes (Rcpp::IntegerVector,
Rcpp:NumericVector, Rcpp::Function, Rcpp::Environment, ...) that makes it
easier to manipulate R objects of matching types (integer vectors, functions,
environments, etc ...).
Rcpp takes advantage of C++ language features such as the explicit
constructor / destructor lifecycle of objects to manag...
2010 Dec 22
0
Rcpp 0.9.0 and RcppClassic 0.9.0
...few key
points are highlighted below. More details are in the NEWS and ChangeLog
files included in the package.
===== Overview =====
Rcpp is an R package and associated C++ library that facilitates integration
of C++ code in R packages.
The package features a complete set of C++ classes (Rcpp::IntegerVector,
Rcpp:NumericVector, Rcpp::Function, Rcpp::Environment, ...) that makes it
easier to manipulate R objects of matching types (integer vectors, functions,
environments, etc ...).
Rcpp takes advantage of C++ language features such as the explicit
constructor / destructor lifecycle of objects to manag...