Loosen signature for repeat()

Accept any AbstractArray as first argument, and any iterable
for inner and outer arguments. Use tuples by default rather
than arrays, and allow passing an empty collection to mean
no-op.

Author: nalimilan

Diff for: base/abstractarraymath.jl

@@ -200,31 +200,61 @@ function repmat(a::AbstractVector, m::Int)
     return b
 end
 
-# Generalized repmat
-function repeat{T}(A::AbstractArray{T};
-                   inner::Array{Int} = ones(Int, ndims(A)),
-                   outer::Array{Int} = ones(Int, ndims(A)))
+"""
+    repeat(A::AbstractArray; inner=(), outer=())
+
+Construct an array by repeating the entries of `A`. The i-th element of `inner` specifies
+the number of times that the individual entries of the i-th dimension of `A` should be
+repeated. The i-th element of `outer` specifies the number of times that a slice along the
+i-th dimension of `A` should be repeated.
+
+```jldoctest
+julia> repeat(1:2, inner=2)
+4-element Array{Int64,1}:
+ 1
+ 1
+ 2
+ 2
+
+julia> repeat(1:2, outer=2)
+4-element Array{Int64,1}:
+ 1
+ 2
+ 1
+ 2
+
+julia> repeat([1 2; 3 4], inner=(2, 1), outer=(1, 3))
+4×6 Array{Int64,2}:
+ 1  2  1  2  1  2
+ 1  2  1  2  1  2
+ 3  4  3  4  3  4
+ 3  4  3  4  3  4
+```
+"""
+function repeat(A::AbstractArray;
+                inner=ntuple(_->1, ndims(A)),
+                outer=ntuple(_->1, ndims(A)))
     ndims_in = ndims(A)
     length_inner = length(inner)
     length_outer = length(outer)
-    ndims_out = max(ndims_in, length_inner, length_outer)
 
-    if length_inner < ndims_in || length_outer < ndims_in
-        throw(ArgumentError("inner/outer repetitions must be set for all input dimensions"))
-    end
+    length_inner >= ndims_in || throw(ArgumentError("number of inner repetitions ($(length(inner))) cannot be less than number of dimensions of input ($(ndims(A)))"))
+    length_outer >= ndims_in || throw(ArgumentError("number of outer repetitions ($(length(outer))) cannot be less than number of dimensions of input ($(ndims(A)))"))
+
+    ndims_out = max(ndims_in, length_inner, length_outer)
 
-    inner = vcat(inner, ones(Int,ndims_out-length_inner))
-    outer = vcat(outer, ones(Int,ndims_out-length_outer))
+    inner = vcat(collect(inner), ones(Int,ndims_out-length_inner))
+    outer = vcat(collect(outer), ones(Int,ndims_out-length_outer))
 
     size_in = size(A)
     size_out = ntuple(i->inner[i]*size(A,i)*outer[i],ndims_out)::Dims
     inner_size_out = ntuple(i->inner[i]*size(A,i),ndims_out)::Dims
 
-    indices_in = Array(Int, ndims_in)
-    indices_out = Array(Int, ndims_out)
+    indices_in = Vector{Int}(ndims_in)
+    indices_out = Vector{Int}(ndims_out)
 
     length_out = prod(size_out)
-    R = Array(T, size_out)
+    R = similar(A, size_out)
 
     for index_out in 1:length_out
         ind2sub!(indices_out, size_out, index_out)

Diff for: base/docs/helpdb/Base.jl

@@ -4300,16 +4300,6 @@ Return an iterator over all keys in a collection. `collect(keys(d))` returns an
 """
 keys
 
-"""
-    repeat(A, inner = Int[], outer = Int[])
-
-Construct an array by repeating the entries of `A`. The i-th element of `inner` specifies
-the number of times that the individual entries of the i-th dimension of `A` should be
-repeated. The i-th element of `outer` specifies the number of times that a slice along the
-i-th dimension of `A` should be repeated.
-"""
-repeat
-
 """
     ReentrantLock()
 

Diff for: doc/stdlib/linalg.rst

@@ -979,12 +979,35 @@ Linear algebra functions in Julia are largely implemented by calling functions f
 
    Construct a matrix by repeating the given matrix ``n`` times in dimension 1 and ``m`` times in dimension 2.
 
-.. function:: repeat(A, inner = Int[], outer = Int[])
+.. function:: repeat(A::AbstractArray; inner=(), outer=())
 
    .. Docstring generated from Julia source
 
    Construct an array by repeating the entries of ``A``\ . The i-th element of ``inner`` specifies the number of times that the individual entries of the i-th dimension of ``A`` should be repeated. The i-th element of ``outer`` specifies the number of times that a slice along the i-th dimension of ``A`` should be repeated.
 
+   .. doctest::
+
+       julia> repeat(1:2, inner=2)
+       4-element Array{Int64,1}:
+        1
+        1
+        2
+        2
+
+       julia> repeat(1:2, outer=2)
+       4-element Array{Int64,1}:
+        1
+        2
+        1
+        2
+
+       julia> repeat([1 2; 3 4], inner=(2, 1), outer=(1, 3))
+       4×6 Array{Int64,2}:
+        1  2  1  2  1  2
+        1  2  1  2  1  2
+        3  4  3  4  3  4
+        3  4  3  4  3  4
+
 .. function:: kron(A, B)
 
    .. Docstring generated from Julia source

Diff for: test/arrayops.jl

@@ -502,53 +502,86 @@ let
     @test isequal(cumsum(A,2),A2)
     @test isequal(cumsum(A,3),A3)
 
-    R = repeat([1, 2], inner = [1], outer = [1])
+    R = repeat([1, 2])
     @test R == [1, 2]
-    R = repeat([1, 2], inner = [2], outer = [1])
+    R = repeat([1, 2], inner=1)
+    @test R == [1, 2]
+    R = repeat([1, 2], outer=1)
+    @test R == [1, 2]
+    R = repeat([1, 2], inner=(1,))
+    @test R == [1, 2]
+    R = repeat([1, 2], outer=(1,))
+    @test R == [1, 2]
+    R = repeat([1, 2], inner=[1])
+    @test R == [1, 2]
+    R = repeat([1, 2], outer=[1])
+    @test R == [1, 2]
+    R = repeat([1, 2], inner=1, outer=1)
+    @test R == [1, 2]
+    R = repeat([1, 2], inner=(1,), outer=(1,))
+    @test R == [1, 2]
+    R = repeat([1, 2], inner=[1], outer=[1])
+    @test R == [1, 2]
+
+    R = repeat([1, 2], inner=2)
+    @test R == [1, 1, 2, 2]
+    R = repeat([1, 2], outer=2)
+    @test R == [1, 2, 1, 2]
+    R = repeat([1, 2], inner=(2,))
     @test R == [1, 1, 2, 2]
-    R = repeat([1, 2], inner = [1], outer = [2])
+    R = repeat([1, 2], outer=(2,))
     @test R == [1, 2, 1, 2]
-    R = repeat([1, 2], inner = [2], outer = [2])
+    R = repeat([1, 2], inner=[2])
+    @test R == [1, 1, 2, 2]
+    R = repeat([1, 2], outer=[2])
+    @test R == [1, 2, 1, 2]
+
+    R = repeat([1, 2], inner=2, outer=2)
     @test R == [1, 1, 2, 2, 1, 1, 2, 2]
-    R = repeat([1, 2], inner = [1, 1], outer = [1, 1])
+    R = repeat([1, 2], inner=(2,), outer=(2,))
+    @test R == [1, 1, 2, 2, 1, 1, 2, 2]
+    R = repeat([1, 2], inner=[2], outer=[2])
+    @test R == [1, 1, 2, 2, 1, 1, 2, 2]
+
+    R = repeat([1, 2], inner = (1, 1), outer = (1, 1))
     @test R == [1, 2]''
-    R = repeat([1, 2], inner = [2, 1], outer = [1, 1])
+    R = repeat([1, 2], inner = (2, 1), outer = (1, 1))
     @test R == [1, 1, 2, 2]''
-    R = repeat([1, 2], inner = [1, 2], outer = [1, 1])
+    R = repeat([1, 2], inner = (1, 2), outer = (1, 1))
     @test R == [1 1; 2 2]
-    R = repeat([1, 2], inner = [1, 1], outer = [2, 1])
+    R = repeat([1, 2], inner = (1, 1), outer = (2, 1))
     @test R == [1, 2, 1, 2]''
-    R = repeat([1, 2], inner = [1, 1], outer = [1, 2])
+    R = repeat([1, 2], inner = (1, 1), outer = (1, 2))
     @test R == [1 1; 2 2]
 
     R = repeat([1 2;
-                3 4], inner = [1, 1], outer = [1, 1])
+                3 4], inner = (1, 1), outer = (1, 1))
     @test R == [1 2;
                   3 4]
     R = repeat([1 2;
-                3 4], inner = [1, 1], outer = [2, 1])
+                3 4], inner = (1, 1), outer = (2, 1))
     @test R == [1 2;
                   3 4;
                   1 2;
                   3 4]
     R = repeat([1 2;
-                3 4], inner = [1, 1], outer = [1, 2])
+                3 4], inner = (1, 1), outer = (1, 2))
     @test R == [1 2 1 2;
                   3 4 3 4]
     R = repeat([1 2;
-                3 4], inner = [1, 1], outer = [2, 2])
+                3 4], inner = (1, 1), outer = (2, 2))
     @test R == [1 2 1 2;
                   3 4 3 4;
                   1 2 1 2;
                   3 4 3 4]
     R = repeat([1 2;
-                3 4], inner = [2, 1], outer = [1, 1])
+                3 4], inner = (2, 1), outer = (1, 1))
     @test R == [1 2;
                   1 2;
                   3 4;
                   3 4]
     R = repeat([1 2;
-                3 4], inner = [2, 1], outer = [2, 1])
+                3 4], inner = (2, 1), outer = (2, 1))
     @test R == [1 2;
                   1 2;
                   3 4;
@@ -558,13 +591,13 @@ let
                   3 4;
                   3 4]
     R = repeat([1 2;
-                3 4], inner = [2, 1], outer = [1, 2])
+                3 4], inner = (2, 1), outer = (1, 2))
     @test R == [1 2 1 2;
                   1 2 1 2;
                   3 4 3 4;
                   3 4 3 4;]
     R = repeat([1 2;
-                3 4], inner = [2, 1], outer = [2, 2])
+                3 4], inner = (2, 1), outer = (2, 2))
     @test R == [1 2 1 2;
                   1 2 1 2;
                   3 4 3 4;
@@ -574,33 +607,33 @@ let
                   3 4 3 4;
                   3 4 3 4]
     R = repeat([1 2;
-                3 4], inner = [1, 2], outer = [1, 1])
+                3 4], inner = (1, 2), outer = (1, 1))
     @test R == [1 1 2 2;
                   3 3 4 4]
     R = repeat([1 2;
-                3 4], inner = [1, 2], outer = [2, 1])
+                3 4], inner = (1, 2), outer = (2, 1))
     @test R == [1 1 2 2;
                   3 3 4 4;
                   1 1 2 2;
                   3 3 4 4]
     R = repeat([1 2;
-                3 4], inner = [1, 2], outer = [1, 2])
+                3 4], inner = (1, 2), outer = (1, 2))
     @test R == [1 1 2 2 1 1 2 2;
                   3 3 4 4 3 3 4 4]
     R = repeat([1 2;
-                3 4], inner = [1, 2], outer = [2, 2])
+                3 4], inner = (1, 2), outer = (2, 2))
     @test R == [1 1 2 2 1 1 2 2;
                   3 3 4 4 3 3 4 4;
                   1 1 2 2 1 1 2 2;
                   3 3 4 4 3 3 4 4]
     R = repeat([1 2;
-                3 4], inner = [2, 2], outer = [1, 1])
+                3 4], inner = (2, 2), outer = [1, 1])
     @test R == [1 1 2 2;
                   1 1 2 2;
                   3 3 4 4;
                   3 3 4 4]
     R = repeat([1 2;
-                3 4], inner = [2, 2], outer = [2, 1])
+                3 4], inner = (2, 2), outer = (2, 1))
     @test R == [1 1 2 2;
                   1 1 2 2;
                   3 3 4 4;
@@ -610,13 +643,13 @@ let
                   3 3 4 4;
                   3 3 4 4]
     R = repeat([1 2;
-                3 4], inner = [2, 2], outer = [1, 2])
+                3 4], inner = (2, 2), outer = (1, 2))
     @test R == [1 1 2 2 1 1 2 2;
                   1 1 2 2 1 1 2 2;
                   3 3 4 4 3 3 4 4;
                   3 3 4 4 3 3 4 4]
     R = repeat([1 2;
-                3 4], inner = [2, 2], outer = [2, 2])
+                3 4], inner = (2, 2), outer = (2, 2))
     @test R == [1 1 2 2 1 1 2 2;
                   1 1 2 2 1 1 2 2;
                   3 3 4 4 3 3 4 4;
@@ -625,17 +658,25 @@ let
                   1 1 2 2 1 1 2 2;
                   3 3 4 4 3 3 4 4;
                   3 3 4 4 3 3 4 4]
+    @test_throws ArgumentError repeat([1 2;
+                                       3 4], inner=2, outer=(2, 2))
+    @test_throws ArgumentError repeat([1 2;
+                                       3 4], inner=(2, 2), outer=2)
+    @test_throws ArgumentError repeat([1 2;
+                                       3 4], inner=(2,), outer=(2, 2))
+    @test_throws ArgumentError repeat([1 2;
+                                       3 4], inner=(2, 2), outer=(2,))
 
     A = reshape(1:8, 2, 2, 2)
-    R = repeat(A, inner = [1, 1, 2], outer = [1, 1, 1])
+    R = repeat(A, inner = (1, 1, 2), outer = (1, 1, 1))
     T = reshape([1:4; 1:4; 5:8; 5:8], 2, 2, 4)
     @test R == T
     A = Array(Int, 2, 2, 2)
     A[:, :, 1] = [1 2;
                   3 4]
     A[:, :, 2] = [5 6;
                   7 8]
-    R = repeat(A, inner = [2, 2, 2], outer = [2, 2, 2])
+    R = repeat(A, inner = (2, 2, 2), outer = (2, 2, 2))
     @test R[1, 1, 1] == 1
     @test R[2, 2, 2] == 1
     @test R[3, 3, 3] == 8
@@ -645,6 +686,19 @@ let
     @test R[7, 7, 7] == 8
     @test R[8, 8, 8] == 8
 
+    R = repeat(1:2)
+    @test R == [1, 2]
+    R = repeat(1:2, inner=1)
+    @test R == [1, 2]
+    R = repeat(1:2, inner=2)
+    @test R == [1, 1, 2, 2]
+    R = repeat(1:2, outer=1)
+    @test R == [1, 2]
+    R = repeat(1:2, outer=2)
+    @test R == [1, 2, 1, 2]
+    R = repeat(1:2, inner=(3,), outer=(2,))
+    @test R == [1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2]
+
     A = rand(4,4)
     for s in Any[A[1:2:4, 1:2:4], sub(A, 1:2:4, 1:2:4)]
         c = cumsum(s, 1)