Calculator User Manual

Appendix A: Functions and Instructions 483
8992APPA.DOC TI-89 / TI-92 Plus: Appendix A (US English) Susan Gullord Revised: 02/23/01 1:48 PM Printed: 02/23/01 2:21 PM Page 483 of 132
PtOff
CATALOG
PtOff
x
,
y
PtOff
xList
,
yList
Displays the Graph screen and turns off the
screen pixel nearest to window coordinates
(
x
,
y
).
PtOff 2,4
¸
PtOn
CATALOG
PtOn
x
,
y
PtOn
xList
,
yList
Displays the Graph screen and turns on the
screen pixel nearest to window coordinates
(
x
,
y
).
PtOn 3,5
¸
ptTest()
CATALOG
ptTest (
x
,
y
)
⇒
Boolean constant expression
ptTest (
xList
,
yList
)
⇒
Boolean constant expression
Returns
true
or
false
. Returns
true
only if the
screen pixel nearest to window coordinates
(
x
,
y
) is on.
ptTest(3,5)
¸
true
PtText
CATALOG
PtText
string
,
x
,
y
Displays the Graph screen and places the
character string
string
on the screen at the
pixel nearest the specified (
x, y
) window
coordinates.
string
is positioned with the upper-left corner
of its first character at the coordinates.
PtText "sample",3,5
¸
PxlChg
CATALOG
PxlChg
row
,
col
PxlChg
rowList
,
colList
Displays the Graph screen and reverses the
pixel at pixel coordinates (
row
,
col
).
Note: Regraphing erases all drawn items.
PxlChg 2,4
¸
PxlCrcl
CATALOG
PxlCrcl
row
,
col
,
r
[
,
drawMode
]
Displays the Graph screen and draws a circle
centered at pixel coordinates (
row
,
col
) with a
radius of
r
pixels.
If
drawMode
= 1, draws the circle (default).
If
drawMode
= 0, turns off the circle.
If
drawMode
= -1, inverts pixels along the
circle.
Note: Regraphing erases all drawn items. See
also
Circle
.
TI-89:
PxlCrcl 40,80,30,1
¸
TI-92 Plus:
PxlCrcl 50,125,40,1
¸