idlwave-shell-graphics-window-size

idlwave-shell-graphics-window-size is a variable defined in `idlw-shell.el'.
Its value is

(500 400)

Documentation:
Size of IDL graphics windows popped up by special IDLWAVE command.
The command is `C-c C-d C-f' and accepts as a prefix the window nr.
A command like `WINDOW,N,xsize=XX,ysize=YY' is sent to IDL.

You can customize this variable.