add support for true scalar functions

src/image.jl

@@ -120,7 +120,8 @@ function _sample(f::FeFunction)
                 (x .- A[:, 1])
             ε = eps()
             if all(xloc .>= -ε) && sum(xloc) <= 1 + ε
-                out[fcolon..., I] .= evaluate(f, xloc)
+                # use view here to handle scalar data assigment as well
+                view(out, fcolon..., I) .= evaluate(f, xloc)
             end
         end
     end