expanded select to also deal with ranges.

Project.toml

@@ -11,9 +11,9 @@ Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 
 [compat]
-PaddedViews = "0.5.8, 0.5.9, 0.5.10, 0.5.11"
-OffsetArrays = "1, 1.12"
-julia = "1, 1.6, 1.7, 1.8"
+PaddedViews = "0.5.8, 0.5.9, 0.5.10, 0.5.11, 0.5.12"
+OffsetArrays = "1, 1.12, 1.13, 1.14"
+julia = "1, 1.6, 1.7, 1.8, 1.9, 1.10, 1.11"
 
 [extras]
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"

src/selection_tools.jl

@@ -5,7 +5,7 @@ export slice
 """
     slice(arr, dim, index)
 
-Return a `N` dimensional slice (where one dimensions has size 1) of the N-dimensional `arr` at the index position
+Return a `N` dimensional slice view (where one dimensions has size 1) of the N-dimensional `arr` at the index position (or range)
 `index` in the `dim` dimension of the array.
 It holds `size(out)[dim] == 1`.
 
@@ -22,7 +22,7 @@ julia> NDTools.slice(x, 1, 1)
  1  2  3
 ```
 """
-function slice(arr::AbstractArray{T, N}, dim::Integer, index::Integer) where {T, N}
+function slice(arr::AbstractArray{T, N}, dim::Integer, index::Union{Integer, UnitRange}) where {T, N}
     inds = slice_indices(axes(arr), dim, index)
     return @view arr[inds...]
 end
@@ -33,6 +33,9 @@ end
  # Arguments:
 `a` should be the axes obtained by `axes(arr)` of an array.
 `dim` is the dimension to be selected and `index` the index of it.
+`index` can be an integer or a range,but the dimensions is always kepts
+
+ # Returns: a tuple of ranges used for slicing
 
 Examples
 ```jldoctest
@@ -47,6 +50,12 @@ function slice_indices(a::NTuple{N, T}, dim::Integer, index::Integer) where {T,
     return inds
 end
 
+function slice_indices(a::NTuple{N, T}, dim::Integer, index::UnitRange) where {T, N}
+    inds = ntuple(i -> i == dim ? (a[i][index]) : (first(a[i]):last(a[i])), 
+                  Val(N))
+    return inds
+end
+
 """
     expand_dims(x, ::Val{N})
 

test/selection_tools.jl

@@ -8,6 +8,11 @@
         x = randn((5,2,3,4))
         y = NDTools.slice(x, 1, 4)
         @test x[4:4, :, :, :] == y
+        y = NDTools.slice(x, 1, 2:3)
+        @test x[2:3, :, :, :] == y
+        y = NDTools.slice(x, 4, 4:4)
+        @test x[:, :, :, 4:4] == y
+
 
         x = randn((5))
         y = NDTools.slice(x, 1, 5)