Type: | Package |
Title: | 'Rcpp' Interface to 'sparsepp' |
Version: | 1.22 |
Date: | 2018-09-19 |
Description: | Provides interface to 'sparsepp' - fast, memory efficient hash map. It is derived from Google's excellent 'sparsehash' implementation. We believe 'sparsepp' provides an unparalleled combination of performance and memory usage, and will outperform your compiler's unordered_map on both counts. Only Google's 'dense_hash_map' is consistently faster, at the cost of much greater memory usage (especially when the final size of the map is not known in advance). |
License: | BSD_3_clause + file LICENSE |
Encoding: | UTF-8 |
URL: | https://github.com/greg7mdp/sparsepp, https://github.com/dselivanov/r-sparsepp |
BugReports: | https://github.com/dselivanov/r-sparsepp/issues |
Suggests: | Rcpp |
RoxygenNote: | 6.0.1 |
NeedsCompilation: | no |
Packaged: | 2018-09-22 16:08:38 UTC; dmitry |
Author: | Gregory Popovitch [aut, cph], Google Inc [aut, cph], Dmitriy Selivanov [cre] |
Maintainer: | Dmitriy Selivanov <selivanov.dmitriy@gmail.com> |
Repository: | CRAN |
Date/Publication: | 2018-09-22 16:30:03 UTC |
sparsepp
Description
sparsepp
provides bindings to the
sparsepp - fast, memory efficient hash map for C++.
sparsepp
is an open source C++ library derived from Google's
excellent sparsehash implementation, but considerably outperform it - https://github.com/greg7mdp/sparsepp/blob/master/bench.md.
It aims to achieve the following objectives:
A drop-in alternative for unordered_map and unordered_set.
Extremely low memory usage (typically about one byte overhead per entry).
Very efficient, typically faster than your compiler's unordered map/set or Boost's.
C++11 support (if supported by compiler).
Single header implementation - just copy sparsepp.h to your project and include it.
Tested on Windows (vs2010-2015, g++), linux (g++, clang++) and MacOS (clang++).
Author(s)
Maintainer: Dmitriy Selivanov selivanov.dmitriy@gmail.com
Authors:
Gregory Popovitch greg7mdp@gmail.com [copyright holder]
Google Inc [copyright holder]
See Also
Useful links:
Report bugs at https://github.com/dselivanov/r-sparsepp/issues
Examples
## Not run:
library(Rcpp)
code = "
// [[Rcpp::plugins(cpp11)]]
#include <Rcpp.h>
using namespace std;
using namespace Rcpp;
// drop-in replacement for unordered_map
//#include <unordered_map>
#include <sparsepp/spp.h>
//[[Rcpp::depends(sparsepp)]]
using spp::sparse_hash_map;
// @export
// [[Rcpp::export]]
IntegerVector word_count(CharacterVector v) {
//unordered_map<string, int> smap;
sparse_hash_map<string, int> smap;
for(auto x: v) {
smap[as<string>(x)] ++;
}
IntegerVector res(smap.size());
int i = 0;
for(auto s:smap) {
res[i]=s.second;
i++;
}
return(res);
}"
f = tempfile(, fileext = ".cpp")
writeLines(code, f)
sourceCpp(f)
unlink(f)
word_count(sample(letters, 100, T))
## End(Not run)