beautypg.com

Texas Instruments TITANIUM TI-89 User Manual

Page 442

background image

Differential Equation Graphing

442

10. Use the

Data/Matrix Editor

(

O) to

create a new data variable named

errorlog

.

Note:

errorlog

lets you combine the data

in

rklog

and

eulerlog

so that you can view

the two sets of data side by side.

11. In this new data variable, define the

c1

,

c2

, and

c3

column headers to refer to data

in

rklog

and

eulerlog

. Also, enter column

titles as shown.

To define a column header, move the
cursor to that column, press

†, type the

reference expression (such as

rklog[1]

for

c1

), and press

¸.

Note:

rklog[1]

and

rklog[2]

refer to

column 1 and 2 in

rklog

, respectively.

Likewise with

eulerlog[2]

.

12. In the

Data/Matrix Editor

, press

„. Then

press

, and define

Plot 1

for the

RK

data, as shown to the right.

13. Define

Plot 2

for the

Euler

data. Use the

values shown to the right.

Plot Type=xyline
Mark=Cross
x=c1
y=c3

14. Return to the Y= Editor, press

3, and

set

Graph = FUNCTION

.

Ê

c1=rklog[1] or

c1=eulerlog[1]

Ë

c2=rklog[2]

Ì

c3= eulerlog[2]

К

Л

М