Texas Instruments TI-85 User Manual
Page 22
B-22
TI-85/TI-86 Graphing Calculators
Copyright © Houghton Mifflin Company. All rights reserved.
TI-86
Position the cursor over the
L
1
at the top of
the first column.
Replace the
L
1
values with
L
1
-
1992
values by
pressing
F3
(
NAMES
) , the menu key under
L
1
, and
then press
–
1992
ENTER
.
Instead of an actual year, the input now represents
the number of years after 1992.
1.4.5 PLOTTING DATA
Any functions you have in the
y(x)=
list will graph when you plot
data. Therefore, you should delete them or turn them off before drawing a scatter plot.
Access the
y(x)=
graphing list. If any entered function
is no longer needed, delete it with
F4
(
DELf
) or clear
it with
CLEAR
.
If you want the function to remain but do not want it to
graph, position the cursor in that function location and
press
F5
(
SELCT
) .
A Òturned offÓ function.
To graph data on the TI-85:
The TI-85 command
Scatter
L
1
,
L
2
draws a scatter plot of
L
1
versus
L
1
. However, you must set
an appropriate
RANGE
before using this command. Program
STPLT
found in the TI-85/TI-86
Appendix automates this task.
Press
PRGM
and then press
F1
(
NAMES
) .
Find the name
STPLT
(press
MORE
if necessary).
Press the
F
-key corresponding
to the location of
STPLT
to
run the program.
Press
CLEAR
to remove the menu from the bottom
of the screen for a better view.
A scatter plot is drawn of the data with the
L
1
data as the
input data and the
L
2
data as the output data.
¥ Program
STPLT
sets the x and y-axis tick marks to
0
so they do not interfere with your
view of the scatter plot.
¥ Because the dots the calculator uses to plot data are sometimes difficult to see when
overdrawing the model of best fit, the program places a small box around each data
point. (The boxes may appear a slightly different size with different screen settings.)
¥ Even though the TI-85 generally allows you to call lists by any names you want, you must
enter the input data in the list named
L
1
and the output data in the list named
L
2
when
using program
STPLT
.
¥ Lists
L
1
and
L
2
must be of the same length or an error message results.
¥ It is not possible to trace a scatter plot drawn on the TI-85.