Texas Instruments PLUS TI-89 - Manual (Page 329)

312 Chapter 17: Programming
17PROGRM.DOC TI-89/TI-92 Plus: Programming (English) Susan Gullord Revised: 02/23/01 1:14 PM Printed: 02/23/01 2:18 PM Page 312 of 40
This example uses Dialog...EndDlog to create dialog boxes for input
and output. It uses Loop...EndLoop to calculate the result.
:prog4()
:Prgm
:Dialog
: Title "Enter an integer"
: Request "Integer",n
:EndDlog
:expr(n)! n
:0! temp:0! i
:Loop
: temp+i! temp
: i+1! i
: If i>n
: Exit
:EndLoop
:Dialog
: Title "The answer is"
: Text string(temp)
:EndDlog
:EndPrgm
This example uses the TI -89 / TI-92 Plus built-in functions to calculate
the result without using a loop.
:prog5()
:Prgm
:Input "Enter an integer",n
:sum(seq(i,i,1,n))! temp
:Disp temp
:EndPrgm
Function Used in this example to:
seq Generate the sequence of integers from 1 to n .
seq( expression, var, low, high [,step])
sum Sum the integers in the list generated by seq .
Example 4
Example 5
Note: Because Input
returns n as a number, you
do not need to use expr to
convert n.
expression used to generate the sequence
Converts string entered
with Request to an
expression.
variable that will be incremented
Defines a dialog box
for input.
initial and final values of var
increment for var ;
if omitted, uses 1.
Defines a dialog
box for output.
Calculates sum.
Displays output on
Program I/O screen.
Prompts for input on
Program I/O screen.
Loop calculation.