To: J3                                                     J3/26-222
From: Soren Rasmussen & HPC
Subject: Edits to replace the NUM_IMAGES example
Date: 2026-October-26


1. Introduction
---------------

This paper contains edits to 17.9.162 NUM_IMAGES, paragraph 6, Example.


The issues with this example are
  1. Performs a naive / non-scalable push-broadcast through a coarray, instead
     of calling CO_BROADCAST which would be the preferred method to do this.
     But an example rewritten to use CO_BROADCAST would no longer need
     NUM_IMAGES, so it wouldn't illustrate the procedure.
  2. "READ (6,*) P" code has Unit 6, which is processor dependent and is
     conventionally connected to output, so reading from it is not portable.

2. Edits to 26-007r2
--------------------

[507:26-34] 17.9.162 NUM_IMAGES, paragraph 6, Example.

Replace the current example paragraph:

"
Example. The following code uses image 1 to read data and broadcast it to
         other images.
   REAL :: P[*]
   IF (THIS_IMAGE()==1) THEN
     READ (6,*) P
     DO I = 2, NUM_IMAGES()
       P[I] = P
     END DO
   END IF
   SYNC ALL
"

with:

"
Example. The following statement prints the index of the invoking image and
         the number of images in the current team.

  PRINT *, "This is image", THIS_IMAGE(), "of", NUM_IMAGES()
"

The replacement represents the customary "hello world" example often
shown in tutorials of SPMD (single program, multiple data) programming
models such as MPI and multi-image Fortran: each image
reports its own image index and the number of images in the current team.