parallel-sort 0.2.0

Cython interface to parallel sorting routines

parallel-sort

This module provides a simple Cython interface to parallel sorting algorithms available in C++. It provides functions for in-place and out-of-place sorts, as well as indirect sorting (aka. "argsort").

By default it requires a C++17-capable compiler, and will use the standard std::sortroutine with the parallel execution policy introduced in that standard. For older compilers without C++17 support, the GNU Parallel Mode sorting routines may be used instead.

Usage

import parallel_sort
import numpy as np

x = np.random.random(size=10000)

x_sorted = parallel_sort.sort(x)

assert np.all(np.diff(x) >= 0) # x is now sorted

Note that these routines are "unstable" sorts, meaning that the ordering of equal elements in the original array is not guaranteed to be preserved.

Installing

Requirements: numpy, C++17-capable g++, Cython (only for installation from source).

On Linux, installing from wheel via pip should "just work":

pip install parallel_sort

On Mac, it is important to ensure that gcc is used to compile the module rather than the default Apple-provided clang, which can be done by prefixing the install command with CC=$(brew --prefix gcc)/bin/gcc-13 (substituting your gcc version as appropriate).

GNU Parallel Mode option

For older compilers that do not support C++17, the module can use the GNU Parallel Mode library instead. To build without C++17, clone the repository and set use_cxx17 = False in setup.py. Then run:

pip install -e .

to compile and install the module.

Note for Apple Silicon Macs

If the module builds OK, but importing it fails with an error "undefined reference to aarch64_ldadd4_acq_rel", try rebuilding with the following command

CFLAGS=-mno-outline-atomics CC=$(brew --prefix gcc)/bin/gcc-13 pip install --no-cache-dir -e .