Randmat(), Randnorm(), Randpoly() – Texas Instruments TITANIUM TI-89 User Manual
Page 862: Randseed, Rclgdb, Rclpic, Real(), 862 appendix a: functions and instructions
862
Appendix A: Functions and Instructions
randMat()
MATH/Probability menu
randMat(
numRows
,
numColumns
)
⇒
⇒
⇒
⇒
matrix
Returns a matrix of integers between -9 and 9 of
the specified dimension.
Both arguments must simplify to integers.
RandSeed 1147
¸
Done
randMat(3,3)
¸
8 л 3 6
л
2 3 л 6
0 4 л 6
Note: The values in this matrix will change
each time you press ¸.
randNorm()
MATH/Probability menu
randNorm(
mean
,
sd
)
⇒
⇒
⇒
⇒
expression
Returns a decimal number from the specific
normal distribution. It could be any real number
but will be heavily concentrated in the interval
[
mean
-3ù
sd
,
mean
+3ù
sd
].
RandSeed 1147
¸
Done
randNorm(0,1)
¸
.492
...
randNorm(3,4.5)
¸
ì
3.543
...
randPoly()
MATH/Probability menu
randPoly(
var
,
order
)
⇒
⇒
⇒
⇒
expression
Returns a polynomial in
var
of the specified order.
The coefficients are random integers in the range
ë 9 through 9. The leading coefficient will not be
zero.
order
must be 0–99.
RandSeed 1147
¸
Done
randPoly(x,5)
¸
л
2ш x
5
+3ø x
4
м
6ш x
3
+4ø xì 6
RandSeed
MATH/Probability menu
RandSeed
number
If
number
= 0, sets the seeds to the factory
defaults for the random-number generator. If
number
ƒ 0, it is used to generate two seeds,
which are stored in system variables
seed1
and
seed2
.
RandSeed 1147
¸
Done
rand()
¸
.158
...
RclGDB
CATALOG
RclGDB
GDBvar
Restores all the settings stored in the Graph
database variable
GDBvar
.
For a listing of the settings, see
StoGDB
.
Note: It is necessary to have something saved in
GDBvar
before you can restore it.
RclGDB GDBvar
¸
Done
RclPic
CATALOG
RclPic
picVar
[,
row
,
column
]
Displays the Graph screen and adds the picture
stored in
picVar
at the upper left-hand corner pixel
coordinates (
row
,
column
) using OR logic.
picVar
must be a picture data type.
Default coordinates are (0, 0).
real()
MATH/Complex menu
real(
expression1
)
⇒
⇒
⇒
⇒
expression
Returns the real part of the argument.
Note: All undefined variables are treated as real
variables. See also
imag()
.
real(2+3
i
)
¸
2
real(z)
¸
z
real(x+iy)
¸
x