Appendix A: Functions and Instructions 459
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 459 of 132
iPart() MATH/Number menu
iPart(number) ⇒ integer
iPart(list1) ⇒ list
iPart(matrix1) ⇒ matrix
Returns the integer part of the argument.
For lists and matrices, returns the integer
part of each element.
The argument can be a real or a complex
number.
iPart(ë1.234) ¸ë1.
iPart({3/2,ë2.3,7.003}) ¸
{1
ë2. 7.
}
isPrime() MATH/Test menu
isPrime(number) ⇒ Boolean constant expression
Returns true or false to indicate if number is a
whole number ‚ 2 that is evenly divisible only
by itself and 1.
If number exceeds about 306 digits and has no
factors 1021, isPrime(number) displays an
error message.
If you merely want to determine if number is
prime, use isPrime() instead of factor(). It is
much faster, particularly if number is not
prime and has a second-largest factor that
exceeds about five digits.
IsPrime(5) ¸true
IsPrime
(
6
)
¸
fa
l
se
Function to find the next prime after a
specified number:
Define nextPrim(n)=Func:Loop:
n+
1
!n:if isPrime
(
n
)
:return n:
En
d
Loop:En
d
Func
¸
Done
nextPrim(7) ¸11
Item CATALOG
Item itemNameString
Item itemNameString, label
Valid only within a Custom...EndCustm or
ToolBar...EndTBar block. Sets up a drop-down
menu element to let you paste text to the
cursor position (Custom) or branch to a label
(ToolBar).
Note: Branching to a label is not allowed
within a Custom block.
See Custom example.
Lbl CATALOG
Lbl labelName
Defines a label with the name labelName in
the program.
You can use a Goto labelName instruction to
transfer program control to the instruction
immediately following the label.
labelName must meet the same naming
requirements as a variable name.
Program segment:
©
:L
bl
lbl1
:InputStr "Enter passwor
d
",
str
1
:If str1ƒpassword
: Goto
lbl1
:Disp "We
l
come to ..."
©