;;;-*-lisp-*-
(comment)

(progn 
 (load '((gjc)gjc lisp))
 (defaultf  '((dsk graphs)))

 (load 'demo)
 (setq prinlength 7)
 (setq read-pause-time 0.1)

 (cursorpos 'c tyo)
 (format tyo 
"This is a very short demo of graphics.
To get the demo type (DEMO) which invokes the
lisp function DEMO defined by this file.
What you will see is a sequence of lisp forms
which if you typed would have the effect that
you see.
")
 (defun pause () (format tyo "~&-pause-") (cursorpos 'n))
 (defun hpause () (cursorpos 'top) (pause))
 (setq demo-forms
       '((or (get 'plot 'version) (load 'plot))
	 (comment "Set the input and output numeric radix to TEN.")
	 (setq base 10. ibase 10.)
	 (gcall graphic-stream 'open 'dsk '((graphs) demo ards))
	 (comment "set the number of points.")
	 (setq plotnum 200)
	 (plot (times 3 x (cos (times 4 x)) (sin x)) x -5 5)
	 (hpause)
	 (plot sin -3.1416 3.1416)
	 (pause)
	 (comment "Or you can define a function.")
	 (defun f1 (x) (*$ x x))
	 (pause)
	 (plot f1 -3 3)
	 (pause)
	 (comment "there is a nice function for making spirals")
	 (defun sp (n m)
		(draw-spiral graphic-stream 1.5 0.0 0.0 n m))
	 (comment "use the auto-scaling of PLOT to set up the window.")
	 (pause)
	 (progn (plot x x -1 1) (sp 33 33))
	 (hpause)
	 (gcall graphic-stream 'cursorpos 'c)
	 (sp 75. 3.)
	 (hpause)
	 (sp 75. 5.)
	 (hpause)
	 (comment " how about some 3d-graphics? ")
	 (or (get 'plot3 'version) (load 'plot3))
	 (gcall graphic-stream 'set-window -0.8 0.8 -0.8 0.8)
	 (comment "set the euler angles. ")
	 (gcall 3d-stream 'Set-theta -1.0)
	 (gcall 3d-stream 'set-phi 0.1)
	 (gcall 3d-stream 'set-psi 0.4)
	 (gcall graphic-stream 'cursorpos 'c)
	 (mobius 100 2)
	 (hpause)
	 (torus 100 10)
	 (gcall graphic-stream 'close 'dsk)
	 (comment "that is all. enjoy!")))
 '*)