'format compact' => less syntax

self assess:
    C) 13x4
    E) vertcat; different columns

### julia notes:

built-in types seem to default to just an array instead of, eg, 3x1 or 1x3.

can transform with "'"; A'' != A?

to vert/horiz cat, need to explicitly 

julia> size([1,2,3])
(3,)

julia> size([1,2,3]')
(1,3)

julia> size([1,2,3]'')
(3,1)