Texas Instruments TI-89 Manual Book page 502

PxlText
CATALOG
PxlText string, row, col
Displays the Graph screen and places
character string
at pixel coordinates (
is positioned with the upper-left corner
string
of its first character at the coordinates.
Note: Regraphing erases all drawn items.
PxlVert
CATALOG
PxlVert col [, drawMode]
Draws a vertical line down the screen at pixel
position
If
drawMode
If
drawMode
If
drawMode
or off to on (inverts pixels along the line).
Note: Regraphing erases all drawn items. See
also
LineVert
QR
MATH/Matrix menu
QR matrix, qMatName, rMatName[ , tol]
Calculates the Householder QR factorization
of a real or complex
and R matrices are stored to the specified
MatNames
matrix is upper triangular.
Optionally, any matrix element is treated as
zero if its absolute value is less than
tolerance is used only if the matrix has
floating-point entries and does not contain
any symbolic variables that have not been
assigned a value. Otherwise,
If you use ¥ ¸ or set the mode to
Exact/Approx=APPROXIMATE
are done using floating-point arithmetic.
If is omitted or not used, the default
tol
tolerance is calculated as:
ë 14 ù max(dim(matrix))
5
E
ù rowNorm(matrix)
on the screen, starting
string
).
,
row col
.
col
= 1, draws the line (default).
= 0, turns off the line.
= -1, turns a line that is on to off
.
. The resulting Q
matrix
. The Q matrix is unitary. The R
is ignored.
tol
, computations
PxlText "sample
TI-89:
text",20,10 ¸
PxlText "sample
TI-92 Plus:
text",20,50 ¸
PxlVert 50,1 ¸
The floating-point number (9.) in
causes results to be calculated in floating-
point form.
[1,2,3;4,5,6;7,8,9.]!m1 ¸
QR m1,qm,rm ¸
. This
tol
qm ¸
8.124...
0.
rm ¸
0.
[m,n;o,p]!m1 ¸
Appendix A: Functions and Instructions
m1
1 2
4 5
7 8
.123... .904... .408...
.492... .301... ë.816...
ë.301...
.861... .408...
9.601... 11.078...
.904... 1.809...
0. 0.
m
[
o
3
6
9.
Done
n
]
p
485