
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
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