README.md

In matloff/Rth: Rth: Parallel R through Thrust

Rth

What Is This?

Rth is a package of functions written in Thrust, callable from R. It thus provides to R programmers a set of parallel applications that run on both GPUs and multicore systems

Thrust is a C++ package for parallel processing. It was originally designed as a high-level approach to GPU programming, but actually can be compiled to multiple backends--GPUs (CUDA) and multicore (OpenMP, TBB). This ability to have the same parallel code run on both GPU and multicore systems is extremely valuable. (You need not have a GPU to run the multicore backends.)

Operations are high-level, such as sorting, selecting, searching and prefix scan. From these basic building blocks, a myriad of parallel applications can be coded.

For example, consider Rth's rthorder(), which (in one of its options) serves as a parallel version of R's rank(). It first calls Thrust's sort_by_key() function, and then uses Thrust's scatter() function to permute the results in a way that produces the proper ranks.

R programmers can use Rth without knowing C++, Thrust, OpenMP or CUDA! But those who do know C++/Thrust can easily develop their own apps using the Rth approach.

Pretty Good Parallelism

The Pretty Good Privacy package (PGP) gave the world encryption which, though not optimal, was simple to use and readily available. With Rth, the idea is to have PGP mean "pretty good parallelism"--not necessarily optimal, but easy to develop and with the key virtue that the same code gives reasonably good performance on both GPUs and multicore.

Package Installation and Platform Requirements

You will need to have the correct build environment set up. Exactly what that means depends on whether you wish to build Rth for use with a gpu or multicore.

If you have a CUDA-capable NVIDIA GPU, you will need the nvcc compiler and CUDA development package.

For the multicore case, you will need a C++ compiler with an OpenMP library (this excludes clang++ at the time of writing). GNU g++ should be sufficient. TBB is also accommodated.

To install, unpack or clone the package, and read the INSTALL file.

License and Copying

Authors:

• Norm Matloff (creator, author), Drew Schmidt (author) and Max Matsumoto (author); special credit to Max for getting the package to work with autoconf on all three parallel platforms

The project is licensed under the GNU General Public License (GPL) version >= 2. Copyright 2012-2017

matloff/Rth documentation built on May 21, 2019, 12:55 p.m.