XL Fortran Enterprise Edition for AIX : User's Guide - IBM

Appendix A. Sample Fortran Programs
The following programs are provided as coding examples for XL Fortran. A
number of these samples illustrate various aspects of SMP programming that may
be new to many users. If you are new to SMP programming, you should examine
these samples to gain a better understanding of the SMP coding style. Every
attempt has been made to internally document key areas of the source to assist you
in this effort.
You can compile and execute the first program to verify that the compiler is
installed correctly and your user ID is set up to execute Fortran programs.
Example 1 - XL Fortran Source File
PROGRAM CALCULATE
!
! Program to calculate the sum of up to n values of x**3
! where negative values are ignored.
!
IMPLICIT NONE
INTEGER I,N
REAL SUM,X,Y
READ(*,*) N
SUM=0
DO I=1,N
READ(*,*) X
IF (X.GE.0) THEN
Y=X**3
SUM=SUM+Y
END IF
END DO
WRITE(*,*) ’This is the sum of the positive cubes:’,SUM
END
Execution Results
Here is what happens when you run the program:
$ a.out
5
37
22
-4
19
6
This is the sum of the positive cubes: 68376.00000
© Copyright IBM Corp. 1990, 2004 405