keywords arguments of same length as series get grouped

src/args.jl

@@ -854,7 +854,7 @@ end
 # expecting a mapping of "group label" to "group indices"
 function extractGroupArgs{T, V<:AVec{Int}}(idxmap::Dict{T,V}, args...)
     groupLabels = sortedkeys(idxmap)
-    groupIds = VecI[collect(idxmap[k]) for k in groupLabels]
+    groupIds = Vector{Int}[collect(idxmap[k]) for k in groupLabels]
     GroupBy(groupLabels, groupIds)
 end
 

src/series.jl

@@ -515,6 +515,13 @@ end
         @series begin
             label     --> string(glab)
             idxfilter --> groupby.groupIds[i]
+            for (key,val) in d
+                length(args) == 0 && break
+                if key != :group && isa(val, AbstractArray) && size(val,1) == size(args[1],1)
+                    n = ndims(val)
+                    :($key) := val[groupby.groupIds[i], fill(Colon(), n-1)...]
+                end
+            end
             args
         end
     end