promote a number of examples to 'inst/' folder

Author: kevinushey

.Rbuildignore

@@ -9,6 +9,4 @@
 ^README.md
 ^doc$
 ^src/.*\.o$
-^examples/
-^gallery/
 ^gen/

examples/.gitignore

@@ -1,3 +1,5 @@
+// Print the SIMD capabilities of your processor.
+
 // [[Rcpp::depends(RcppParallel)]]
 #define RCPP_PARALLEL_USE_SIMD
 #include <RcppParallel.h>

examples/boost-simd-abssum.cpp

@@ -1,11 +1,16 @@
+// Demonstrates how Boost.SIMD could be used to compute the dot product
+// of two vectors, using a lower-level iteration over packs.
+//
+// See: http://nt2.metascale.fr/doc/html/tutorials/processing_data_the_simd_way.html
+
 // [[Rcpp::depends(RcppParallel)]]
 #define RCPP_PARALLEL_USE_SIMD
 #include <RcppParallel.h>
+using namespace RcppParallel;
+
 #include <Rcpp.h>
 using namespace Rcpp;
 
-// http://nt2.metascale.fr/doc/html/tutorials/processing_data_the_simd_way.html
-
 template <typename Value>
 Value simd_dot_impl(Value* first1, Value* last1, Value* first2)
 {
@@ -44,10 +49,12 @@ double simd_dot(NumericVector lhs, NumericVector rhs)
 }
 
 /*** R
+set.seed(123)
 lhs <- rnorm(1024 * 1000)
 rhs <- rnorm(1024 * 1000)
+stopifnot(all.equal(simd_dot(lhs, rhs), sum(lhs * rhs)))
 
-all.equal(simd_dot(lhs, rhs), sum(lhs * rhs))
+library(microbenchmark)
 microbenchmark(
    simd = simd_dot(lhs, rhs),
    R = sum(lhs * rhs)

examples/boost-simd-accumulate.cpp

@@ -1,3 +1,6 @@
+// Showcases how a stateful functor can be used with `simdFor()`,
+// for arbitrary operations over a range of values.
+
 // [[Rcpp::depends(RcppParallel)]]
 #define RCPP_PARALLEL_USE_SIMD
 #include <RcppParallel.h>
@@ -28,11 +31,11 @@ class Accumulator
 };
 
 // [[Rcpp::export]]
-double vectorProd(NumericVector x) {
+double simdProd(NumericVector x) {
    return simdFor(x.begin(), x.end(), Accumulator());
 }
 
 /*** R
 x <- 1:16
-vectorProd(x)
+stopifnot(all.equal(prod(x), simdProd(x)))
 */

examples/simd-operations.Rmd

@@ -1,11 +1,16 @@
+// The 'hello world' of Boost.SIMD, showing how packs can be
+// used and manipulated at a low level.
+//
+// See: http://nt2.metascale.fr/doc/html/tutorials/simd_hello_world.html
+
 // [[Rcpp::depends(RcppParallel)]]
 #define RCPP_PARALLEL_USE_SIMD
 #include <RcppParallel.h>
+using namespace RcppParallel;
+
 #include <Rcpp.h>
 using namespace Rcpp;
 
-// http://nt2.metascale.fr/doc/html/tutorials/simd_hello_world.html
-
 // [[Rcpp::export]]
 void HelloWorld()
 {

examples/boost-simd-capabilities.cpp …s/boost-simd/boost-simd-capabilities.cppexamples/boost-simd-capabilities.cpp renamed to inst/examples/boost-simd/boost-simd-capabilities.cpp examples/boost-simd-capabilities.cpp renamed to inst/examples/boost-simd/boost-simd-capabilities.cpp

@@ -1,3 +1,6 @@
+// Shows how 'simdMapReduce()' can be used to efficiently
+// transform and accumulate values.
+
 // [[Rcpp::depends(RcppParallel)]]
 #define RCPP_PARALLEL_USE_SIMD
 #include <RcppParallel.h>
@@ -43,9 +46,9 @@ double simdVar(NumericVector x)
 }
 
 /*** R
-x <- rnorm(1024 * 10000)
-var(x)
-simdVar(x)
+set.seed(123)
+x <- rnorm(1024)
+stopifnot(all.equal(var(x), simdVar(x)))
 library(microbenchmark)
 microbenchmark(var(x), simdVar(x))
 */