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 [ën,ë1].
RandSeed 1147 ¸Done
rand() ¸.158...
ran
d(
6
)
¸
5
ran
d(
ë
1
00
)
¸
ë49
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 ë3 6
ë2 3 ë6
0 4 ë6
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-3ùsd, mean+3ùsd].
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 ë9 through 9. The leading
coefficient will not be zero.
order must be 0–99.
RandSeed 1147 ¸Done
ran
d
Po
l
y
(
x,5
)
¸
ë2øx5+3øx
4
ì6øx
3
+4øxì6
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.)