Fix bug in interaction of scalar terms for row tables (#206)

* add test to reproduce #185

* only call `vec` if necessary in `kron_insideout`

* use length(size()) instead of length()

* use isa AbstractArray check instead of dims

* bump patch version

Author: kleinschmidt

Project.toml

@@ -1,6 +1,6 @@
 name = "StatsModels"
 uuid = "3eaba693-59b7-5ba5-a881-562e759f1c8d"
-version = "0.6.17"
+version = "0.6.18"
 
 [deps]
 DataAPI = "9a962f9c-6df0-11e9-0e5d-c546b8b5ee8a"

src/terms.jl

@@ -510,7 +510,9 @@ reshape_last_to_i(i, a::AbstractMatrix) = reshape(a, size(a,1), ones(Int, i-1)..
 # table, some will be vectors, possibly some matrices
 function kron_insideout(op::Function, args...)
     args = (reshape_last_to_i(i,a) for (i,a) in enumerate(args))
-    vec(broadcast(op, args...))
+    out = broadcast(op, args...)
+    # flatten array output to vector
+    out isa AbstractArray ? vec(out) : out
 end
 
 function row_kron_insideout(op::Function, args...)

test/modelmatrix.jl

@@ -398,4 +398,10 @@
         @test_throws ArgumentError modelcols(f, t)
     end
 
+    @testset "#185 - interactions of scalar terms for row tables" begin
+        t = (a = rand(10), b = rand(10), c = rand(10))
+        f = apply_schema(@formula(0 ~ a&b&c), schema(t))
+        @test vec(modelcols(f.rhs, t)) == modelcols.(Ref(f.rhs), Tables.rowtable(t))
+    end
+    
 end