Calculator User Manual

Appendix A: Functions and Instructions 433
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 433 of 132
0b
binaryNumber
0h
hexadecimalNumber
Without a prefix,
integer1
is treated as
decimal. The result is displayed in decimal,
regardless of the
Base
mode.
Define
CATALOG
Define
funcName
(
arg1Name, arg2Name, ...
) =
expression
Creates
funcName
as a user-defined function.
You then can use
funcName
()
, just as you use
built-in functions
.
The function evaluates
expression
using the supplied arguments and
returns the result.
funcName
cannot be the name of a system
variable or built-in function.
The argument names are placeholders; you
should not use those same names as
arguments when you use the function.
Note: This form of
Define
is equivalent to
executing the expression:
expression!funcName
(
arg1Name,arg2Name
)
.
This command also can be used to define
simple variables; for example, Define a=3.
Define g(x,y)=2x
ì
3y
¸
Done
g
(1
,2
)
¸
ë
4
1
!
a:2
!
b
:g
(
a,
b)
¸
ë
4
Define h(x)=when(x<2,2x-3,
ë
2x+3
)
¸
Done
h(
ë
3
)
¸
ë
9
h(
4
)
¸
ë
5
Define eigenvl(a)=
cZeros
(d
et
(
i
d
entity
(d
im
(
a
)
[1])-x
ù
a),x)
¸
Done
eigenv
l([
ë
1
,2;4,3
])
¸
{
2
ø
3 - 1
11
ë
(2
ø
3 + 1)
11
}
Define
funcName
(
arg1Name, arg2Name, ...
) = Func
block
EndFunc
Is identical to the previous form of
Define
,
except that in this form, the user-defined
function
funcName
()
can execute a block of
multiple statements.
block
can be either a single statement or a
series of statements separated with the “:”
character.
block
also can include expressions
and instructions (such as
If
,
Then
,
Else
, and
For
). This allows the function
funcName
()
to
use the
Return
instruction to return a specific
result.
Note: It is usually easier to author and edit
this form of Function in the program editor
rather than on the entry line.
Define g(x,y)=Func:If x>y Then
:Return x:Else:Return y:EndIf
:EndFunc
¸
Done
g(3,
ë
7)
¸
3
A binary number can have up to
32 digits. A hexadecimal number
can have up to 8.
Zero, not the letter O, followed by b or h.