Texas Instruments TI-89 Titanium User Manual page 216

Creating a Multi-Statement Function
You can also create a user-defined function whose definition consists of multiple
statements. The definition can include many of the control and decision-making
structures ( ,
If ElseIf
For information about similarities and differences between functions and
Note:
programs, refer to Programming.
For example, suppose you want to create a function that sums a series of reciprocals
based on an entered integer (
1 1
+ + +
-- - ----------- - ...
n n 1 –
When creating the definition of a multi-statement function, it may be helpful to visualize it
first in a block form.
Ê
Func
Ë
Local temp,i
If fPart(nn)ƒ0 or nn{0
Ì
Return "bad argument"
0!temp
Í
For i,nn,1,M1
approx(temp+1/i)!temp
EndFor
Î
Return temp
Ê
EndFunc
Ê
Func and EndFunc must begin and end the function.
Ë
Variables not in the argument list must be declared as local.
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, , etc.) used in programming.
Return
):
n
1
-- -
1
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