Contour Plots - Texas Instruments TI-89 Manual Book

Contour Plots

Selecting the Graph
Format Style
Tip: From the Graph
screen, you can switch from
one graph format style to
the next (skipping
IMPLICIT
) by pressing:
PLOT
:
Í
TI-89
TI-92 Plus : F
Note: Pressing:
:
TI-89 Í
: F
TI-92 Plus
to select
CONTOUR LEVELS
does not affect the viewing
angle, view, or Labels
format as it does if you use:
: ¥ Í
TI-89
: ¥ F
TI-92 Plus
Note: These examples use
the same x , y , and z
Window variable values as a
ZoomStd viewing cube. If
you use ZoomStd, press Z
to look down the z axis.
Note: Do not confuse the
contours with the grid lines.
The contours are darker.
In a contour plot, a line is drawn to connect adjacent points on
the 3D graph that have the same z value. This section
discusses the
CONTOUR LEVELS
graph format styles.
In 3D graphing mode, define an equation and graph it as you would
any 3D equation, with the following exception. Display the
dialog box by pressing ƒ
FORMATS
editor, or Graph screen. Then set:
Style = CONTOUR LEVELS
– or –
Style = WIRE AND CONTOUR
¦
For
CONTOUR LEVELS
The viewing angle is set initially so that you are viewing the
contours by looking down the z axis. You can change the
viewing angle as necessary.
The graph is shown in expanded view. To switch between
expanded and normal view, press p.
The format is set to
Labels
¦
For
WIRE AND CONTOUR
frame view. The viewing angle, view (expanded or normal), and
format retain their previous settings.
Labels
Style z1(x,y)=(xò yì yò x) / 390
CONTOUR
LEVELS
CONTOUR
LEVELS
WIRE AND
CONTOUR
and
WIRE AND CONTOUR
from the Y= Editor, Window
9
, only the contours are shown.
automatically.
OFF
, the contours are drawn on a wire
z1(x,y)=xñ +.5yñ ì 5
Looking down z axis
Using eyeq=20, eyef=70, eye =0
Chapter 10: 3D Graphing
GRAPH
167