Physics 410 - Computational Physics - UBC - Fall 2004

Physics 410: Fortran Programming

Please report all errors/typos. etc to choptuik@physics.ubc.ca

Last updated October 12, 2005

The source code described below and in class can also be found on the phys410 account on the lnx machines in ~phys410/f77/ex1, ~phys410/f77/ex2, ... (organized by lecture).
Some Online References for Fortran 77 Programming
- Professional Programmer's Guide to Fortran 77, by Clive Page, (PDF)
- PGI Fortran 77 Reference Manual 5.2
- PGI User's Guide 5.2
- PGI Tools Guide1
- Guide to available PGI documentation
Lecture 1 (Oct 11)
- Using Fortran and C in the Unix Environment (PDF).
- Recommended environment variable settings for course machines can be found HERE
Combined handouts: (PDF) for Lectures 2 through 6 (does NOT include Notes on Fortran arrays from Lecture 5)
Lecture 2 (Oct 18)
- fdemo1.f: Program demonstrating some essential Fortran 77 language elements
- fdemo1-output: Output from fdemo1
- Makefile: Note: Beware of cutting-and-pasting text to and from Makefiles. All lines which specify an action (shell command) for updating a target must begin with a TAB character.
Lecture 3 (Oct 20 & Oct 25)
- fdemo2.f: Program demonstrating Fortran 77 usage of character variables.
- fdemo2-output: Output from fdemo2.
- first100: Test file used in mysum and dvfrom examples. Session trace showing, among other things, how first-100 was created.
- mysum.f: Reads real*8 values from stdin and writes sum on stdout.
  - Less-commented version mysum-s.f and sample output.
  - Version that dispenses with the dreaded go to statement: mysum-ng.f, that also illustrates another method of detecting EOF in Fortran. (See also Go to Statement Considered Harmful and Real Programmers Don't Use Pascal for rather varied views [as well as tone!] on the go to debate.
- dvfrom.f: Subroutine which reads real*8 vector from file (or stdin). Testing routine tdvfrom.f and sample output.
- dvto.f: Subroutine which writes real*8 vector to file (or stdout). Testing routine tdvto.f and sample output.
- Makefile and output from make.
Lecture 4 (Oct 25)
- Please review the HTML notes concerning the use of Fortran and C in the Unix Environment.
- tdrand48.f: Demonstrates use of random number generator (drand48). Program output.
- tsavedata.f: Demonstrates use of SAVE and DATA statements. Program output.
- tsub.f: Demonstrates essentials of argument passing in Fortran. Program output.
- texternal.f: Demonstrates EXTERNAL statement and passing subprogram names as arguments to other subprograms. Program output.
- tcommon.f: Demonstrates use of COMMON blocks for communicating variables between program units. Program output.
- tcommon1.f: Demonstrates RECOMMMENDED implementation and use of common blocks using an 'include' file: coma.inc.
- Makefile for above executables and output from make.
Lecture 5 (Oct 27)
- Notes on Fortran 77 arrays: (PDF)
- arraydemo.f: Demonstrates a general technique for writing Fortran 77 programs which define and manipulate multi-dimensional arrays whose bounds are determined at run time. Program output.
- Makefile for above executable.
- arraydemo90.f: Fortran 90 implementation of above example, illustrating f90's dynamical memory allocation facilities. Makefile for this example.
Lecture 6 (Oct 27)
- A brief synopsis of the IEEE floating point standard from the PSC. Another PAGE with links to much more additional information, including What Every Computer Scientist Should Know About Floating-Point Arithmetic, by David Goldberg (PS).
- meps.f: Computes approximate real*8 machine epsilon. Sun (IEEE) output. PC Linux output.
- catprec.f: Illustrates catastrophic precision loss due to subtraction of nearly-equal floating point values. Program output.
- dmroutines.f: Two dimensional array (matrix) routines:
  - dmmmult: Matrix-matrix multiply (square matrices only)
  - dmfrom: Read matrix from file or stdin
  - dmto: Write matrix to file or stdout
- tdm.f: Test driver for dmroutines.f. Program output.
- Makefile for above executables.
Miscellaneous programs and scripts
- t2d.f: Program to test understanding of Fortran 77 array storage scheme.
- Sample output from nth, a filter (shell-script) which selects specified columns (separated by white space) from standard output and writes them to standard output.
Additional Material