[Rcpp-devel] Calling igraph from within Rcpp

[Pavankumar Gurazada]

As a part of utilizing network data drawn at random before further
processing, I am trying to call a couple of functions from the igraph package
at the beginning of each iteration. The code I use is as follows:



#define ARMA_64BIT_WORD#include <RcppArmadillo.h>
// [[Rcpp::depends(RcppArmadillo)]]// [[Rcpp::plugins(cpp11)]]
using namespace Rcpp;

using arma::sp_mat;
// [[Rcpp::export]]
sp_mat adj_mat(int n, double p) {

Environment igraph("package:igraph");
Function game_er = igraph["erdos.renyi.game"];
Function get_adjacency = igraph["get.adjacency"];

List g = game_er(Named("n", n), Named("p", p));

NumericMatrix A_m = get_adjacency(Named("g", g));

sp_mat A = as<sp_mat>(A_m);

return A;}


/*** R
set.seed(20130810)
library(igraph)

adj_mat(100, 0.5)*/

sourceCpp("Hooking-R-in-cpp.cpp")
set.seed(20130810)
library(igraph)
adj_mat(100, 0.5)

Error in adj_mat(100, 0.5) :
Not compatible with requested type: [type=S4; target=double].

From the error it looks like I am passing a S4 class to a double? Where is
the error?

[Dirk Eddelbuettel]

On 15 March 2018 at 16:29, Pavankumar Gurazada wrote:
| As a part of utilizing network data drawn at random before further
| processing, I am trying to call a couple of functions from the igraph package
| at the beginning of each iteration. The code I use is as follows:

This is a cross-posted (which we discourage) over at StackOverflow at where I
saw it first and already answered it:

https://stackoverflow.com/questions/49299368/calling-igraph-from-within-rcpp

In short, needs these two lines (or equivalent) in the middle:

SEXP g = game_er(Named("n", n), Named("p", p));

S4 A_m = get_adjacency(Named("g", g));


Dirk



| #define ARMA_64BIT_WORD#include <RcppArmadillo.h>
| // [[Rcpp::depends(RcppArmadillo)]]// [[Rcpp::plugins(cpp11)]]
| using namespace Rcpp;
|
| using arma::sp_mat;
| // [[Rcpp::export]]
| sp_mat adj_mat(int n, double p) {
|
| Environment igraph("package:igraph");
| Function game_er = igraph["erdos.renyi.game"];
| Function get_adjacency = igraph["get.adjacency"];
|
| List g = game_er(Named("n", n), Named("p", p));
|
| NumericMatrix A_m = get_adjacency(Named("g", g));
|
| sp_mat A = as<sp_mat>(A_m);
|
| return A;}
|
|
| /*** R
| set.seed(20130810)
| library(igraph)
|
| adj_mat(100, 0.5)*/
|
|
|
| So, while the C++ compiles without warnings, the following error is thrown:
|
| > sourceCpp("Hooking-R-in-cpp.cpp")
| > set.seed(20130810)
| > library(igraph)
| > adj_mat(100, 0.5)
| Error in adj_mat(100, 0.5) :
| Not compatible with requested type: [type=S4; target=double].
|
| >From the error it looks like I am passing a S4 class to a double? Where is
| the error?
| _______________________________________________
| Rcpp-devel mailing list
| Rcpp-***@lists.r-forge.r-project.org
| https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel

[Pavankumar Gurazada]

Yes, apologies for getting too eager! I should have waited.

Post by Dirk Eddelbuettel
| As a part of utilizing network data drawn at random before further
| processing, I am trying to call a couple of functions from the igraph package
This is a cross-posted (which we discourage) over at StackOverflow at where I
https://stackoverflow.com/questions/49299368/calling-
igraph-from-within-rcpp
SEXP g = game_er(Named("n", n), Named("p", p));
S4 A_m = get_adjacency(Named("g", g));
Dirk
| #define ARMA_64BIT_WORD#include <RcppArmadillo.h>
| // [[Rcpp::depends(RcppArmadillo)]]// [[Rcpp::plugins(cpp11)]]
| using namespace Rcpp;
|
| using arma::sp_mat;
| // [[Rcpp::export]]
| sp_mat adj_mat(int n, double p) {
|
| Environment igraph("package:igraph");
| Function game_er = igraph["erdos.renyi.game"];
| Function get_adjacency = igraph["get.adjacency"];
|
| List g = game_er(Named("n", n), Named("p", p));
|
| NumericMatrix A_m = get_adjacency(Named("g", g));
|
| sp_mat A = as<sp_mat>(A_m);
|
| return A;}
|
|
| /*** R
| set.seed(20130810)
| library(igraph)
|
| adj_mat(100, 0.5)*/
|
|
|
|
| > sourceCpp("Hooking-R-in-cpp.cpp")
| > set.seed(20130810)
| > library(igraph)
| > adj_mat(100, 0.5)
| Not compatible with requested type: [type=S4; target=double].
|
| >From the error it looks like I am passing a S4 class to a double? Where is
| the error?
| _______________________________________________
| Rcpp-devel mailing list
| https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
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