stringdist-parallelization

Multithreading and parallelization in <pkg>stringdist</pkg>

Implements an approximate string matching version of R's native
     'match' function. Can calculate various string distances based on edits
     (damerau-levenshtein, hamming, levenshtein, optimal sting alignment), qgrams
     (q-gram, cosine, jaccard distance) or heuristic metrics (jaro, jaro-winkler).
     An implementation of soundex is provided as well. Distances can be computed
     between character vectors while taking proper care of encoding or between
     integer vectors representing generic sequences.

Mark der Loo

stringdist

Approximate String Matching and String Distance Functions

stringdist-parallelization function

The core
  functions of <pkg>stringdist</pkg> are implemented in C. On systems where
  <code>openMP</code> is available, <pkg>stringdist</pkg> will automatically take
  advantage of multiple cores. The
  <href>https://cran.r-project.org/doc/manuals/r-release/R-exts.html#OpenMP-support</href>{section
  on OpenMP} of the
  <href>https://cran.r-project.org/doc/manuals/r-release/R-exts.html</href>{Writing
  R Extensions} manual discusses on what systems OpenMP is available (at the time of writing more or
  less, anywhere except on OSX).<p></p><p>By default, the number of threads to use is taken from <code>options('sd_num_thread')</code>.
When the package is loaded, the value for this option is determined as follows:
<ul><li>The number of available cores is determined with<code>parallel::detectCores()</code></li></ul>
  <item>If available, the environment variable <code>OMP_THREAD_LIMIT</code> is determined</item>
  <item>The number of threads is set to the lesser of <code>OMP_THREAD_LIMIT</code> and the number of detected cores.</item>
  <item>If the number of threads larger then or equal to $4$, and <code>OMP_THREAD_LIMIT</code> is not set, it is set to <code>'sd_num_thread'-1</code></item>.</p>

code

http://cran.r-project.org/package=microbenchmark

stringdist-parallelization: Multithreading and parallelization in stringdist

Description

Arguments

Multithreading and parallelization in <pkg>stringdist</pkg>

eqn

code

href

Details

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