Rand(), Randmat(), Rclgdb – Texas Instruments PLUS TI-89 User Manual
Page 505
488 Appendix A: Functions and Instructions
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 488 of 132
rand()
MATH/Probability menu
rand([
n
])
⇒
expression
n
is an integer
ƒ zero.
With no parameter, returns the next random
number between 0 and 1 in the sequence.
When an argument is positive, returns a
random integer in the interval [1,
n
].
When an argument is negative, returns a
random integer in the interval [ë
n
,ë 1].
RandSeed 1147 ¸
Done
rand() ¸
.158...
rand(6) ¸
5
rand(л 100) ¸
л 49
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) ¸
ì3.543...
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
(Sets the random-number seed.)