SelectTransform with single index (#181)

* Fix up select implementation

* Bump patch

* Uncomment tests

* Tidy up a bit

* Test vector-of-vectors

* Fix up evaluation

Author: willtebbutt

Project.toml

@@ -1,6 +1,6 @@
 name = "KernelFunctions"
 uuid = "ec8451be-7e33-11e9-00cf-bbf324bd1392"
-version = "0.8.3"
+version = "0.8.4"
 
 [deps]
 Compat = "34da2185-b29b-5c13-b0c7-acf172513d20"

src/transform/selecttransform.jl

@@ -17,9 +17,15 @@ set!(t::SelectTransform, dims) = t.select .= dims
 
 duplicate(t::SelectTransform,θ) = t
 
-(t::SelectTransform)(x::AbstractVector) = view(x, t.select)
+(t::SelectTransform)(x::AbstractVector) = _maybe_unwrap(view(x, t.select))
 
-_map(t::SelectTransform, x::ColVecs) = ColVecs(view(x.X, t.select, :))
-_map(t::SelectTransform, x::RowVecs) = RowVecs(view(x.X, :, t.select))
+_maybe_unwrap(x) = x
+_maybe_unwrap(x::AbstractArray{<:Any, 0}) = x[]
+
+_map(t::SelectTransform, x::ColVecs) = _wrap(view(x.X, t.select, :), ColVecs)
+_map(t::SelectTransform, x::RowVecs) = _wrap(view(x.X, :, t.select), RowVecs)
+
+_wrap(x::AbstractVector{<:Real}, ::Any) = x
+_wrap(X::AbstractMatrix{<:Real}, ::Type{T}) where {T} = T(X)
 
 Base.show(io::IO, t::SelectTransform) = print(io, "Select Transform (dims: ", t.select, ")")

test/transform/selecttransform.jl

@@ -109,4 +109,15 @@
             testfunction(ta_col, a, C, 1)
         end
     end
+
+    @testset "single-index" begin
+        t = SelectTransform(4)
+        @testset "$(name)" for (name, x) in [
+            ("Vector{<:Vector}", [randn(6) for _ in 1:3]),
+            ("ColVecs", ColVecs(randn(5, 10))),
+            ("RowVecs", RowVecs(randn(11, 4))),
+        ]
+            @test KernelFunctions._map(t, x) isa AbstractVector{Float64}
+        end
+    end
 end