Merge pull request JuliaLang#4764 from magistere/master

Implement logical indexing for SubArray. Fixes JuliaLang#4763

base/subarray.jl

@@ -263,6 +263,25 @@ function getindex(s::SubArray, is::Integer...)
  s.parent[index]
 end
 
+function getindex_bool_1d(S::SubArray, I::AbstractArray{Bool})
+ n = sum(I)
+ out = similar(S, n)
+ c = 1
+ for i = 1:length(I)
+ if I[i]
+ out[c] = S[i]
+ c += 1
+ end
+ end
+ out
+end
+
+getindex{T}(S::SubArray{T,1}, I::AbstractArray{Bool,1}) = getindex_bool_1d(S, I)
+getindex{T}(S::SubArray{T,2}, I::AbstractArray{Bool,2}) = getindex_bool_1d(S, I)
+getindex{T}(S::SubArray{T,3}, I::AbstractArray{Bool,3}) = getindex_bool_1d(S, I)
+getindex{T}(S::SubArray{T,4}, I::AbstractArray{Bool,4}) = getindex_bool_1d(S, I)
+getindex{T}(S::SubArray{T,5}, I::AbstractArray{Bool,5}) = getindex_bool_1d(S, I)
+
 getindex{T}(s::SubArray{T,1}, I::Range1{Int}) =
  getindex(s.parent, (s.first_index+(first(I)-1)*s.strides[1]):s.strides[1]:(s.first_index+(last(I)-1)*s.strides[1]))
 

test/arrayops.jl

@@ -122,6 +122,13 @@ sA = sub(A, 1:2:3, 1:3:5, 1:2:8)
 @test strides(sA) == (2,9,30)
 @test sA[:] == A[1:2:3, 1:3:5, 1:2:8][:]
 
+# sub logical indexing #4763
+A = sub([1:10], 5:8)
+@test A[A.<7] == [5, 6]
+B = reshape(1:16, 4, 4)
+sB = sub(B, 2:3, 2:3)
+@test sB[sB.>8] == [10, 11]
+
 # slice
 A = reshape(1:120, 3, 5, 8)
 sA = slice(A, 2, :, 1:8)