Texas Instruments PLUS TI-89 - Manual (Page 181)

164 Chapter 10: 3D Graphing
10_3D.DOC TI-89/TI-92 Plus: 3D Graphing (English) Susan Gullord Revised: 02/23/01 11:00 AM Printed: 02/23/01 4:22 PM Page 164 of 22 10_3D.DOC TI-89/TI-92 Plus: 3D Graphing (English) Susan Gullord Revised: 02/23/01 11:00 AM Printed: 02/23/01 4:22 PM Page 164 of 22
When using A and B to animate a graph, think of it as moving the
viewing angle along its “viewing orbit” around the graph.
Moving along this orbit can
cause the z axis to wobble
slightly during the animation
(as you can see in the preview
example on page 154).
To: Do this:
Animate the graph incrementally Press and release the cursor
quickly.
Move along the viewing orbit: A or B
Change the viewing orbit’s
elevation
(primarily increases
or decreases eye f )
: C or D
Animate the graph continuously Press and hold the cursor for
about 1 second, and then
release it.
TI
-
89 : To stop, press N,
¸, ´, or ¥  (space).
TI
-
92 Plus : To stop, press N,
¸, ´, or the space bar.
Change between 4 animation
speeds (increase or decrease the
incremental changes in the
eye
Window variables)
Press « or |.
Change the viewing angle of a non-
animated graph to look along the x,
y, or z axis Press X , Y or Z , respectively.
Return to the initial eye angle
values
Press 0
(zero, not the letter O).
You can also animate a graph by saving a series of graph pictures
and then flipping (or cycling) through those pictures. Refer to
“Animating a Series of Graph Pictures” in Chapter 12: Additional
Graphing Topics. This method gives you more control over the
Window variable values, particularly
eye ψ (page 162), which rotates
the graph.
Animating a 3D Graph Interactively
After plotting any 3D graph, you can change the viewing angle
interactively by using the cursor. Refer to the preview example
on page 154.
The Viewing Orbit
Note: The viewing orbit
affects the eye Window
variables in differing
amounts.
Animating the
Graph
Note: If the graph is shown
in expanded view, it returns
to normal view automatically
when you press a cursor
key.
Tip: After animating the
graph, you can stop and
then re-start the animation
in the same direction by
pressing:
TI - 89: ¸ or j 
TI - 92 Plus: ¸ or space
bar
Tip: During an animation,
you can switch to the next
graph format style by
pressing:
TI - 89: Í
TI - 92 Plus: F
Tip: To see a graphic that
shows the eye angles, refer
to page 162.
Animating a Series
of Graph Pictures