idlwave-shell-frame-parameters

idlwave-shell-frame-parameters is a variable defined in `idlw-shell.el'.
Its value is

((height . 30) (unsplittable))

Documentation:
The frame parameters for a dedicated idlwave-shell frame.
See also `idlwave-shell-use-dedicated-frame'.
The default makes the frame splittable, so that completion works correctly.

You can customize this variable.