Swap adjoint for permutedims in collapse (#397)

* Swap adjoint for permutedims in collapse

This allows collapse to be used with types for which adjoint isn't
defined, such as strings.

It also prevents complex numbers from being conjugated, which may have
come as a surprise to users.

src/combine.jl

@@ -106,7 +106,7 @@ function collapse(ta::TimeArray{T,N,D}, period::Function, timestamp::Function,
 
         if mapped_tstamp != next_mapped_tstamp
           push!(collapsed_tstamps, timestamp(_timestamp(ta)[cluster_startrow:i]))
-          collapsed_values = [collapsed_values; T[value(values(ta)[cluster_startrow:i, j]) for j in 1:ncols]']
+          collapsed_values = [collapsed_values; T[value(values(ta)[cluster_startrow:i, j]) for j in 1:ncols] |> permutedims]
           cluster_startrow = i+1
         end #if
 
@@ -116,7 +116,7 @@ function collapse(ta::TimeArray{T,N,D}, period::Function, timestamp::Function,
     end #for
 
     push!(collapsed_tstamps, timestamp(_timestamp(ta)[cluster_startrow:end]))
-    collapsed_values = [collapsed_values; T[value(values(ta)[cluster_startrow:end, j]) for j in 1:ncols]']
+    collapsed_values = [collapsed_values; T[value(values(ta)[cluster_startrow:end, j]) for j in 1:ncols] |> permutedims]
 
     N == 1 && (collapsed_values = vec(collapsed_values))
     return TimeArray(collapsed_tstamps, collapsed_values, colnames(ta), meta(ta))

test/combine.jl

@@ -33,6 +33,20 @@ end
         @test values(collapse(ohlc, month, first))[2, :] == [104.0, 105.0, 100.0, 100.25]
         @test timestamp(collapse(ohlc, month, first))[2] == Date(2000,2,1)
     end
+
+    # https://github.com/JuliaStats/TimeSeries.jl/pull/397
+    @testset "Array of String" begin
+        A = string.(Char.(rand(97:97+25, size(cl))))
+        ts = timestamp(cl)
+        ta = TimeArray(ts, A)
+
+        let
+            ta = collapse(ta, week, first)
+
+            @test values(ta)[2]    == A[6]
+            @test timestamp(ta)[2] == ts[6]
+        end
+    end
 end