Texas Instruments TI-89 Manual Do Utilizador

3D Graphing

401

Drawing Contours for Specified Z Values

From the Graph screen, display the Draw menu and then select

8:DrwCtour

. The Home

screen is displayed automatically with

DrwCtour

in the entry line. You can then specify

one or more z values individually or generate a sequence of z values.

Some examples are:

Note:

To remove the default contours, use

8 $ and set

ncontour=0

The specified contours are drawn on the current 3D graph. (A contour is not drawn if the
specified z value is outside the viewing cube or if the 3D graph is not defined at that z
value.)

Notes about Contour Plots

For a contour plot:

•

You can use the cursor keys to animate the contour plot.

•

You cannot trace (

…) the contours themselves. However, you can trace the wire

frame as seen when Style=WIRE AND CONTOUR.

•

It may take awhile to evaluate the equation initially.

DrwCtour 5

Draws a contour for z=5.

DrwCtour {1,2,3}

Draws contours for z=1, 2, and 3.

DrwCtour
seq(n,n,

10,10,2)

Draws contours for a sequence of z values
from

10 through 10 in steps of 2 (

10,

etc.).