| author | title | date |
|---|---|---|
Dai ZJ |
SortingLab README |
2019--09-28 |
SortingLab
An alternative implementation of sorting algorithms and APIs. The ultimate aim is to contribute back to Julia base or SortingAlgorithms.jl. However, there is commitment to keep this package's API stable and supported, so other developers can rely on the implementation and API here.
Faster Sort and Sortperm
The main function exported by SortingLab is fsort and fsortperm which generally implements faster algorithms than sort and sortperm for CategoricalArrays.CategoricalVector, Vector{T}, Vector{Union{T, Missing}} where T is
- Int*, UInt*, Float*, String
Usage
using SortingLab;
using Test
N = 1_000_000;
K = 100;
svec = rand("id".*string.(1:N÷K, pad=10), N);
svec_sorted = fsort(svec);
@test issorted(svec_sorted)
@test issorted(svec) == falseTest Passed
# faster string sortperm
sorted_idx = fsortperm(svec)
issorted(svec[sorted_idx]) #true
# in place string sort
fsort!(svec);
issorted(svec) # truetrue
# CategoricalArray sort
using CategoricalArrays
pools = "id".*string.(1:100,3);
byvec = CategoricalArray{String, 1}(rand(UInt32(1):UInt32(length(pools)), N), CategoricalPool(pools, false));
byvec = compress(byvec);
byvec_sorted = fsort(byvec);
@test issorted(byvec_sorted)Test Passed
Sorting Vector{Union{T, Missing}}
For vectors that contain missing, the sort and sortperm performance is often sub-optimal in Base and is not supported in SortingAlgorithms.jl's radixsort implementation. This is solved by SortingLab.jl fsort, see Benchmarks Section
using Test
using Missings: allowmissing
x = allowmissing(rand(1:10_000, 1_000_000))
x[rand(1:length(x), 100_000)] .= missing
using SortingLab
@test isequal(fsort(x), sort(x))Test Passed
Benchmarks
Benchmarking code
using SortingLab;
using BenchmarkTools;
import Random: randstring
N = 1_000_000;
K = 100;
svec = rand("id".*string.(1:N÷K, pad=10), N);
sort_id_1m = @belapsed sort($svec);
radixsort_id_1m = @belapsed radixsort($svec);
sortperm_id_1m = @belapsed sortperm($svec);
fsortperm_id_1m = @belapsed fsortperm($svec);
rsvec = rand([randstring(rand(1:32)) for i = 1:N÷K], N);
sort_r_1m = @belapsed sort($rsvec);
radixsort_r_1m = @belapsed radixsort($rsvec);
sortperm_r_1m = @belapsed sortperm($rsvec);
fsortperm_r_1m = @belapsed fsortperm($rsvec);
using Plots
using StatsPlots
groupedbar(
repeat(["IDs", "Random len 32"], inner=2),
[sort_id_1m, radixsort_id_1m, sort_r_1m, radixsort_r_1m],
group = repeat(["Base.sort","SortingLab.radixsort"], outer = 2),
title = "Strings sort (1m rows): Base vs SortingLab")
savefig("benchmarks/sort_vs_radixsort.png")
groupedbar(
repeat(["IDs", "Random len 32"], inner=2),
[sortperm_id_1m, fsortperm_id_1m, sortperm_r_1m, fsortperm_r_1m],
group = repeat(["Base.sortperm","SortingLab.fsortperm"], outer = 2),
title = "Strings sortperm (1m rows): Base vs SortingLab")
savefig("benchmarks/sortperm_vs_fsortperm.png")Similar package
https://github.com/JuliaCollections/SortingAlgorithms.jl
