Introduction

Running FORTRAN 90 programs on the cluster is similar to running any other serial job. Make sure you’ve read the tutorial for C programs first, to understand the basics.

Serial Example

Let’s try to compile this simple Fortran 90 program:

Download: ..code/hello_serial-f90/hello_serial.f90

To compile this using GCC and create the executable helloworld-f90-gcc, type:

[araim1@maya-usr1 hello_serial-f90]$ gfortran hello_serial.f90 -o hello_serial-f90-gcc
[araim1@maya-usr1 hello_serial-f90]$

Alternatively, to compile using Intel Fortran and create the executable helloworld-f90-pgi, type

[araim1@maya-usr1 hello_serial-f90]$ ifort hello_serial.f90 -o hello_serial-f90-intel
[araim1@maya-usr1 hello_serial-f90]$

Running this program should produce this output:

[araim1@maya-usr1 hello_serial-f90]$ ./helloworld-f90-gcc
Greetings, denizens of planet Earth!
[araim1@maya-usr1 hello_serial-f90]$ ./helloworld-f90-intel
Greetings, denizens of planet Earth!
[araim1@maya-usr1 hello_serial-f90]$ 

Parallel Example

We’ll assume that you already know the fundamentals of MPI execution from the C tutorial. Now let’s create the following program:

Download: ..code/hello_parallel-f90/hello_parallel.f90

Now we can compile the program with

[araim1@maya-usr1 hello_parallel-f90]$ mpif90 hello_parallel.f90 -o hello_parallel

The same compilation command should work even if you’ve changed the switcher to use a different MPI implementation and compiler. Running the compiled program is now exactly the same as running a C MPI program.