Displaying 6 results from an estimated 6 matches for "compute_values_cpp".
2017 Dec 03
5
Rcpp, dyn.load and C++ problems
...written a small C++ function and compile it.
However in R I can't see the function I have defined in C++.
I have read some web-pages about Rcpp and C++ but it is a bit confusion
for me.
Anyway,
This is the C++-code:
#include <Rcpp.h>
using namespace Rcpp;
// [[Rcpp::export]]
List compute_values_cpp(int totalPoints = 1e5, double angle_increment =
0.01, int radius = 400, double grow = 3.64) {
double xn = 0.5;
double angle = 0.1;
double xn_plus_one, yn_plus_one;
NumericVector x(totalPoints);
NumericVector y(totalPoints);
for (int i=0; i<totalPoints; i++) {
xn_plus_one = xn*co...
2017 Dec 03
0
Rcpp, dyn.load and C++ problems
.Call("compute_values_cpp")
Also, if you were passing arguments to the C++ function you would need to
declare the function differently.
Do a search on "Rcpp calling C++ functions from R"
HTH,
Eric
On Sun, Dec 3, 2017 at 3:06 AM, Martin M?ller Skarbiniks Pedersen <
traxplayer at gmail.com> wrote:
>...
2017 Dec 03
0
Rcpp, dyn.load and C++ problems
...with the package?
In essence you _complitely_ missed what Rcpp Attributes does and shows, as
does the (newer) Rcpp Introduction vignette.
More crazy, your file was actually 100% correct. I just added three lines to
_also_ execute R code (and I indented just for clarity)
/*** R
res <- compute_values_cpp()
str(res)
*/
Then in R:
R> library(Rcpp)
R> sourceCpp("/tmp/mmsp.cpp")
R> res <- compute_values_cpp()
R> str(res)
List of 2
$ x: num [1:100000] 199 362 118 302 262 ...
$ y: num [1:100000] 20 40 14.3 39.5 36.9 ...
R...
2017 Dec 03
0
Rcpp, dyn.load and C++ problems
I would go to the source, in this case Dirk Eddelbuettel's (I hope I
spelled it correctly) documentation for Rcpp:
http://dirk.eddelbuettel.com/code/rcpp/Rcpp-attributes.pdf
Note that you need to do
sourceCpp("logistic_map.cpp")
in R instead of building and dyn.load()-ing the object.
HTH,
Peter
On Sun, Dec 3, 2017 at 11:04 AM, Martin M?ller Skarbiniks Pedersen
<traxplayer
2017 Dec 03
1
Rcpp, dyn.load and C++ problems
...would have missed this were it not for luck.
"R has its own list, rcpp-devel" is what I meant to write. For completeness,
we can also test on the command-line as Martin and what I do a lot myself:
edd at bud:~$ r -lRcpp -e'sourceCpp("/tmp/mmsp.cpp")'
R> res <- compute_values_cpp()
R> str(res)
Attaching package: ?utils?
The following objects are masked from ?package:Rcpp?:
.DollarNames, prompt
List of 2
$ x: num [1:100000] 199 362 118 302 262 ...
$ y: num [1:100000] 20 40 14.3 39.5 36.9 ...
You have mail in /var/mail/edd
edd at bud:~$
That uses littler which...
2017 Dec 03
2
Rcpp, dyn.load and C++ problems
On 3 December 2017 at 05:23, Eric Berger <ericjberger at gmail.com> wrote:
>
> Do a search on "Rcpp calling C++ functions from R"
>
Thanks. However search for "Rcpp calling C++ functions from R" gives a lot
of result but I think
some of them are outdated and others don't agree with each other.
Can you point to a specific good on-line guide for me?
Regards