[Rcpp-commits] r3929 - in pkg/Rcpp: . inst/examples inst/examples/Attributes

[noreply at r-forge.r-project.org]

Author: jjallaire
Date: 2012-11-10 20:33:54 +0100 (Sat, 10 Nov 2012)
New Revision: 3929

Added:
   pkg/Rcpp/inst/examples/Attributes/
   pkg/Rcpp/inst/examples/Attributes/Depends.cpp
   pkg/Rcpp/inst/examples/Attributes/Export.cpp
   pkg/Rcpp/inst/examples/Attributes/cppFunction.R
   pkg/Rcpp/inst/examples/Attributes/sourceCpp.R
Modified:
   pkg/Rcpp/ChangeLog
Log:
add some simple examples for attributes and related functions

Modified: pkg/Rcpp/ChangeLog
===================================================================
--- pkg/Rcpp/ChangeLog	2012-11-10 15:31:53 UTC (rev 3928)
+++ pkg/Rcpp/ChangeLog	2012-11-10 19:33:54 UTC (rev 3929)
@@ -1,6 +1,10 @@
 2012-11-10  JJ Allaire <jj at rstudio.org>
 
         * src/Attributes.cpp: add optional hook for inclusion of package types
+        * examples/Attributes/Export.cpp: example use of Rcpp::export
+        * examples/Attributes/Depends.cpp: example use of Rcpp::depends
+        * examples/Attributes/sourceCpp.R: example use of sourceCpp()
+        * examples/Attributes/cppFunction.R: example use of cppFunction()
 
 2012-11-09  Romain Francois <romain at r-enthusiasts.com>
 

Added: pkg/Rcpp/inst/examples/Attributes/Depends.cpp
===================================================================
--- pkg/Rcpp/inst/examples/Attributes/Depends.cpp	                        (rev 0)
+++ pkg/Rcpp/inst/examples/Attributes/Depends.cpp	2012-11-10 19:33:54 UTC (rev 3929)
@@ -0,0 +1,28 @@
+
+// [[Rcpp::depends(RcppArmadillo)]]
+
+#include <RcppArmadillo.h>
+
+using namespace Rcpp;
+
+// [[Rcpp::export]]
+List fastLm(NumericVector yr, NumericMatrix Xr) {
+
+    int n = Xr.nrow(), k = Xr.ncol();
+
+    arma::mat X(Xr.begin(), n, k, false); // reuses memory and avoids extra copy
+    arma::colvec y(yr.begin(), yr.size(), false);
+
+    arma::colvec coef = arma::solve(X, y);      // fit model y ~ X
+    arma::colvec resid = y - X*coef;            // residuals
+
+    double sig2 = arma::as_scalar( arma::trans(resid)*resid/(n-k) );
+                                                // std.error of estimate
+    arma::colvec stderrest = arma::sqrt(
+                    sig2 * arma::diagvec( arma::inv(arma::trans(X)*X)) );
+
+    return List::create(Named("coefficients") = coef,
+                        Named("stderr")       = stderrest
+    );
+}
+

Added: pkg/Rcpp/inst/examples/Attributes/Export.cpp
===================================================================
--- pkg/Rcpp/inst/examples/Attributes/Export.cpp	                        (rev 0)
+++ pkg/Rcpp/inst/examples/Attributes/Export.cpp	2012-11-10 19:33:54 UTC (rev 3929)
@@ -0,0 +1,40 @@
+
+#include <Rcpp.h>
+
+using namespace Rcpp;
+
+// [[Rcpp::export]]
+int fibonacci(const int x) {
+        
+     if (x == 0) return(0);
+     if (x == 1) return(1);
+     
+     return (fibonacci(x - 1)) + fibonacci(x - 2);
+}
+
+
+// [[Rcpp::export("convolveCpp")]]
+NumericVector convolve(NumericVector a, NumericVector b) {
+    
+    int na = a.size(), nb = b.size();
+    int nab = na + nb - 1;
+    NumericVector xab(nab);
+    
+    for (int i = 0; i < na; i++)
+        for (int j = 0; j < nb; j++)
+            xab[i + j] += a[i] * b[j];
+    
+    return xab;
+}
+
+
+// [[Rcpp::export]]
+List lapplyCpp(List input, Function f) {
+    
+    List output(input.size());
+    
+    std::transform(input.begin(), input.end(), output.begin(), f);
+    output.names() = input.names();
+
+    return output;
+}
\ No newline at end of file

Added: pkg/Rcpp/inst/examples/Attributes/cppFunction.R
===================================================================
--- pkg/Rcpp/inst/examples/Attributes/cppFunction.R	                        (rev 0)
+++ pkg/Rcpp/inst/examples/Attributes/cppFunction.R	2012-11-10 19:33:54 UTC (rev 3929)
@@ -0,0 +1,43 @@
+
+library(Rcpp)
+
+cppFunction('
+    NumericVector convolveCpp(NumericVector a, NumericVector b) {
+        
+        int na = a.size(), nb = b.size();
+        int nab = na + nb - 1;
+        NumericVector xab(nab);
+        
+        for (int i = 0; i < na; i++)
+            for (int j = 0; j < nb; j++)
+                xab[i + j] += a[i] * b[j];
+        
+        return xab;
+    }            
+')
+
+convolveCpp(c(1,2,3), matrix(3,3))
+
+
+cppFunction(depends='RcppArmadillo', code='
+    List fastLm(NumericVector yr, NumericMatrix Xr) {
+
+        int n = Xr.nrow(), k = Xr.ncol();
+    
+        arma::mat X(Xr.begin(), n, k, false); // reuses memory and avoids copy
+        arma::colvec y(yr.begin(), yr.size(), false);
+    
+        arma::colvec coef = arma::solve(X, y);      // fit model y ~ X
+        arma::colvec resid = y - X*coef;            // residuals
+    
+        double sig2 = arma::as_scalar( arma::trans(resid)*resid/(n-k) );
+                                                    // std.error of estimate
+        arma::colvec stderrest = arma::sqrt(
+                        sig2 * arma::diagvec( arma::inv(arma::trans(X)*X)) );
+    
+        return List::create(Named("coefficients") = coef,
+                            Named("stderr")       = stderrest
+    );
+}                  
+')
+

Added: pkg/Rcpp/inst/examples/Attributes/sourceCpp.R
===================================================================
--- pkg/Rcpp/inst/examples/Attributes/sourceCpp.R	                        (rev 0)
+++ pkg/Rcpp/inst/examples/Attributes/sourceCpp.R	2012-11-10 19:33:54 UTC (rev 3929)
@@ -0,0 +1,10 @@
+
+library(Rcpp)
+
+sourceCpp("Export.cpp")
+fibonacci(5)
+
+
+sourceCpp("Depends.cpp")
+fastLm(c(1,2,3), matrix(3,3))
+