Merge pull request #57 from michiboo/master

add humanize function to generate pink noise

.travis.yml

@@ -5,7 +5,7 @@ os:
   - osx
 
 julia:
-  - 1.2
+  - 1
   # - nightly # commented to save energy and time
 
 before_script:

Project.toml

@@ -1,19 +1,22 @@
 name = "MusicManipulations"
 uuid = "274955c0-c284-5bf7-b122-5ecd51c559de"
 repo = "https://github.com/JuliaMusic/MusicManipulations.jl.git"
-version = "1.5.0"
+version = "1.6.0"
 
 [deps]
+ARFIMA = "9d0fb3db-ba49-4108-bc86-650b3813b6d5"
 MIDI = "f57c4921-e30c-5f49-b073-3f2f2ada663e"
 MotifSequenceGenerator = "7d228ccb-0fc9-53c8-a429-8c9b5b572bc3"
+Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 Reexport = "189a3867-3050-52da-a836-e630ba90ab69"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 StatsBase = "2913bbd2-ae8a-5f71-8c99-4fb6c76f3a91"
 
 [compat]
+julia = "1.1"
+ARFIMA = "0.3.0"
 MIDI = "1.4.1"
 MotifSequenceGenerator = "1.0"
-julia = "1.1"
 Reexport = "0.2, 0.3, 1"
 StatsBase = "0.32, 0.33"
 

src/MusicManipulations.jl

@@ -8,6 +8,8 @@ include("general.jl")
 include("midifiles.jl")
 include("quantize.jl")
 include("scale.jl")
+include("humanize.jl")
+
 include("data_handling/data_extraction.jl")
 include("data_handling/timeseries.jl")
 

src/humanize.jl

@@ -0,0 +1,37 @@
+export humanize!, humanize
+
+using ARFIMA, Statistics
+const φ0 = ARFIMA.SVector(-0.5, -1.5)
+
+"""
+    humanize!(notes, property, σ, noise = :ARFIMA; kwargs...)
+Humanize given `notes` by adding noise of standard deviation `σ` to their `property`,
+typically either `:position` or `:velocity`. Research[^Datseris2019] suggests that `σ`
+should be around 40 (for `:position`) but that depends on the BPM, and around 10 for `:velocity`.
+
+The `noise` argument decides the type of noise:
+* `:ARFIMA` uses ARFIMA.jl and attempts to generate a power-law correlated (pink) noise.
+  Keywords `d = 0.25, φ = SVector(-0.5, -1.5)` are propagated to function `arfima`.
+* `:white` plain ol' white noise.
+
+Use `humanize` for a non-modifying version.
+
+[^Datseris2019]: Datseris, G., et al. [Microtiming Deviations and Swing Feel in Jazz. Sci Rep 9, 19824 (2019)](https://doi.org/10.1038/s41598-019-55981-3)
+"""
+function humanize!(n::Notes, property, σ, noise = :ARFIMA; d=0.25, φ=φ0)
+    N = length(n)
+    if noise == :ARFIMA
+        ξ = arfima(N, 1.0, d, φ)
+    elseif noise == :white
+        ξ = randn(N)
+    else
+        error("Unrecognized noise type")
+    end
+    ξ .*= σ/std(ξ)
+    for j in 1:N
+        setproperty!(n[j], property, getproperty(n[j], property) + round(Int, ξ[j]))
+    end
+    return n
+end
+
+humanize(notes, args...; kwargs...) = humanize!(copy(notes), args...; kwargs...)

test/humanizer_tests.jl

@@ -0,0 +1,13 @@
+using MusicManipulations, Test, Statistics
+
+@testset "humanize" begin
+
+#test of humanize functionality
+notes = randomnotes(100)
+for n in notes; n.velocity = 100; end
+hnotes = humanize(notes, :velocity, 10)
+@test any(i -> notes[i].velocity ≠ hnotes[i].velocity, 1:length(notes))
+σ = std(velocities(hnotes))
+@test 9.5 ≤ σ ≤ 10.5
+
+end

test/runtests.jl

@@ -9,3 +9,4 @@ include("quantizer_tests.jl")
 include("timeseries.jl")
 include("data_extraction.jl")
 include("scale_tests.jl")
+include("humanizer_tests.jl")