项目作者: thk686

项目描述 :
A strided iterator-adapter for scanning multidimensional legacy buffers in C++
高级语言: C++
项目地址: git://github.com/thk686/strider.git
创建时间: 2017-11-04T04:40:08Z
项目社区:https://github.com/thk686/strider

开源协议:Other

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Strider

Timothy H. Keitt
2018-09-13

“I don’t think he knows about second breakfast” - Meriadoc ‘Merry’ Brandybuck

Adapting multidimensional legacy buffers to the C++ standard library is difficult owing to a lack of strided (address-skipping) iterators. Strider provides an address-skipping pointer adapter. It can be used to scan multidimensional data along any desired margin using the standard library algorithms.

This code snippet computes row sums of a matrix.

  1. for_each(make_strided(begin(x), nr), make_strided(end(x)), [&](const double& y) {
  2. transform(&y, &y + nr, begin(res), begin(res), plus<double>()); });

It is cache and compiler friendly and runs nearly four times faster than R’s built-in rowSums function. See the vignette for details.

The header file is stand-alone and can be used separate from R. It relies on the Boost iterator library.

Installation

  1. devtools::install_github("thk686/strider")

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