Add variations_with_repetitions()

Samayel · Jul 2, 2015 · 989919b · 989919b
1 parent 39f5b94
commit 989919b
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Showing 4 changed files with 14 additions and 10 deletions.
diff --git a/src/Math/combinatorics.jl b/src/Math/combinatorics.jl
@@ -4,23 +4,25 @@ VERSION < v"0.4-" && @reexport using Combinatorics
 
 export
     permutations_with_repetitions,
-#   variations, variations_with_repetitions,
+    variations, variations_with_repetitions,
     combinations_with_repetitions
 
 
-# Base.permutations()
+# permutations{T}(a::AbstractArray{T,1}) = Base.permutations(a)
 
 permutations_with_repetitions{T}(a::AbstractArray{T,1}) =
     variations_with_repetitions(a, length(a))
 
 
 # http://www.aconnect.de/friends/editions/computer/combinatoricode_e.html
-#variations{T}(a::AbstractArray{T,1}, k::Integer) = nothing
+variations{T}(::AbstractArray{T,1}, ::Integer) = nothing
 
-# product(repeated(a, k)...)
-#variations_with_repetitions{T}(a::AbstractArray{T,1}, k::Integer) = nothing
+variations_with_repetitions{T}(a::AbstractArray{T,1}, k::Integer) =
+    @pipe product(repeated(a, k)...) |>            # cartesian product as tuples
+    tmap(t -> [t[end:-1:1]...], Array{T,1}, _)     # convert tuples to arrays
 
-# Base.combinations()
+
+# combinations{T}(a::AbstractArray{T,1}, k::Integer) = Base.combinations(a, k)
 
 combinations_with_repetitions{T}(a::AbstractArray{T,1}, k::Integer) =
     multicombinations(a, k)
diff --git a/src/Math/math.jl b/src/Math/math.jl
@@ -1,5 +1,8 @@
 @reexport module Math
 
+using Brainstorm: tmap
+using Iterators: product, repeated
+using Pipe.@pipe
 using Reexport.@reexport
 
 # @reexport using DecFP

diff --git a/src/lint.jl b/src/lint.jl
@@ -4,6 +4,8 @@ end
 @lintpragma("Ignore undefined module DataStructures.SortedDict")
 @lintpragma("Ignore undefined module Iterators.drop")
 @lintpragma("Ignore undefined module Iterators.imap")
+@lintpragma("Ignore undefined module Iterators.product")
+@lintpragma("Ignore undefined module Iterators.repeated")
 @lintpragma("Ignore undefined module Iterators.take")
 @lintpragma("Ignore undefined module Lint.lintpkg")
 @lintpragma("Ignore undefined module TaylorSeries.Taylor1")
@@ -14,6 +16,7 @@ end
 
 @lintpragma("Ignore undefined module Brainstorm.dropwhile")
 @lintpragma("Ignore undefined module Brainstorm.takewhile")
+@lintpragma("Ignore undefined module Brainstorm.tmap")
 @lintpragma("Ignore undefined module Brainstorm.Math.checked_add")
 @lintpragma("Ignore undefined module Brainstorm.Math.checked_sub")
 @lintpragma("Ignore undefined module Brainstorm.@anon")

diff --git a/test/Math/combinatorics.jl b/test/Math/combinatorics.jl
@@ -12,7 +12,6 @@ function test_combinatorics_permutations()
 end
 
 function test_combinatorics_permutations_with_repetitions()
-#=
     @test collect(permutations_with_repetitions(["a", "b", "c"])) == Array[
         ["a", "a", "a"],
         ["a", "a", "b"],
@@ -44,7 +43,6 @@ function test_combinatorics_permutations_with_repetitions()
     ]
     @test length(permutations_with_repetitions(["a", "b", "c"])) == 27
     @test eltype(permutations_with_repetitions(["a", "b", "c"])) == Array{ASCIIString,1}
-=#
 end
 
 function test_combinatorics_variations()
@@ -69,7 +67,6 @@ function test_combinatorics_variations()
 end
 
 function test_combinatorics_variations_with_repetitions()
-#=
     @test collect(variations_with_repetitions(["a", "b", "c", "d"], 2)) == Array[
         ["a", "a"],
         ["a", "b"],
@@ -90,7 +87,6 @@ function test_combinatorics_variations_with_repetitions()
     ]
     @test length(variations_with_repetitions(["a", "b", "c", "d"], 2)) == 16
     @test eltype(variations_with_repetitions(["a", "b", "c", "d"], 2)) == Array{ASCIIString,1}
-=#
 end
 
 function test_combinatorics_combinations()