Merge pull request #372 from gridap/filtered_array

added filtered arrays

Author: santiagobadia

src/Arrays/Arrays.jl

@@ -41,6 +41,7 @@ export setsize!
 export CompressedArray
 export LocalToGlobalArray
 export LocalToGlobalPosNegArray
+export FilteredCellArray
 
 export kernel_cache
 export kernel_caches
@@ -118,6 +119,8 @@ include("LocalToGlobalArrays.jl")
 
 include("LocalToGlobalPosNegArrays.jl")
 
+include("FilteredArrays.jl")
+
 include("Reindex.jl")
 
 include("IdentityVectors.jl")

src/Arrays/FilteredArrays.jl

@@ -0,0 +1,76 @@
+
+"""
+Array of vectors that combines an `AbstractArray{Array{T,M},N}` and another
+array of masks with the same structure but `Bool` entries, and returns a
+vector with the entries of the original array that are `true` in the mask array,
+i.e., the filtered entries
+"""
+struct FilteredCellArray{T,M,N,L,V} <: AbstractArray{Array{T,M},N}
+  cell_values::L
+  cell_filters::V
+
+  @doc """
+  """
+  function FilteredCellArray(
+    cell_values::AbstractArray{<:AbstractArray},
+    cell_filters::AbstractArray{<:AbstractArray})
+
+    @assert size(cell_values) == size(cell_filters) "Global arrays mismatch"
+
+    T = eltype(eltype(cell_values))
+
+    L = typeof(cell_values)
+    V = typeof(cell_filters)
+
+    # M = ndims(eltype(L))
+    M = 1 # The result is always a vector with the entries
+    N = ndims(L)
+
+    O = ndims(V)
+
+    @assert N == O "Local arrays dim mismatch"
+
+    @assert (eltype(eltype(cell_filters))<: Bool) "Filters are not Booleans"
+
+    new{T,M,N,L,V}(cell_values,cell_filters)
+
+  end
+end
+
+size(a::FilteredCellArray) = size(a.cell_values)
+
+function IndexStyle(::Type{<:FilteredCellArray{T,M,N,L}}) where {T,M,N,L}
+  IndexStyle(L)
+end
+
+function array_cache(a::FilteredCellArray)
+  vals = testitem(a.cell_values)
+  T = eltype(eltype(a.cell_values))
+  r = zeros(T,length(vals))
+  c = CachedArray(r)
+  cv = array_cache(a.cell_values)
+  cb = array_cache(a.cell_filters)
+  (cv,cb,c)
+end
+
+function getindex!(cache,a::FilteredCellArray,i::Integer...)
+  (cv,cb,c) = cache
+  vals = getindex!(cv,a.cell_values,i...)
+  filters = getindex!(cb,a.cell_filters,i...)
+  @assert size(vals) == size(filters) "Local arrays mismatch"
+  setsize!(c,(sum(filters),))
+  r = c.array
+  i = 0
+  for (val,filter) in zip(vals,filters)
+    if filter
+      i += 1
+      r[i] = val
+    end
+  end
+  r
+end
+
+function getindex(a::FilteredCellArray,i::Integer...)
+  cache = array_cache(a)
+  getindex!(cache,a,i...)
+end

test/ArraysTests/FilteredArraysTests.jl

@@ -0,0 +1,51 @@
+module FilteredArrays
+
+using Test
+using Gridap.Arrays
+using Gridap
+using FillArrays
+
+v1 = collect(1:4)
+v2 = collect(5:8)
+v3 = collect(9:12)
+values = [v1,v2,v3]
+ptrs = [1,2,3,3,2,2]
+a = CompressedArray(values,ptrs)
+r = values[ptrs]
+test_array(a,r)
+
+filter = [false, true, true, false]
+filters = Fill(filter,6)
+
+fa = FilteredCellArray(a,filters)
+
+test_array(fa,[a[i][2:3] for i in 1:6])
+
+#
+
+v1 = [ [2  4  3  3]; [2  4  3  3]]
+v2 = [ [5  8  4  3]; [2  4  4  4]]
+v3 = [ [2  2  8  8]; [2  9  8  6]]
+
+values = [v1,v2,v3]
+ptrs = [1,2,3,3,2,2]
+a = CompressedArray(values,ptrs)
+r = values[ptrs]
+test_array(a,r)
+
+b = Array{Bool,2}(undef,2,4)
+b .= true
+b[2,3] = b[1,4] = false
+
+filters = Fill(b,6)
+
+fa = FilteredCellArray(a,filters)
+
+r1 = [2, 2, 4, 4, 3, 3]
+r2 = [5, 2, 8, 4, 4, 4]
+r3 = [2, 2, 2, 9, 8, 6]
+res = [r1,r2,r3]
+r = CompressedArray(res,ptrs)
+test_array(fa,r)
+
+end #module

test/ArraysTests/runtests.jl

@@ -16,6 +16,8 @@ using Test
 
 @testset "LocalToGlobalPosNegArrays" begin include("LocalToGlobalPosNegArraysTests.jl") end
 
+@testset "FilteredArraysTests" begin include("FilteredArraysTests.jl") end
+
 @testset "Tables" begin include("TablesTests.jl") end
 
 @testset "Reindex" begin include("ReindexTests.jl") end