Fortran 77 package FD version 5.30

Package FD contains programs for 2-D P-SV elastic second-order finite differences.

See file fdver.htm for the list of released versions and changes made in this version.

Package FD employs package FORMS for unified memory management and unified compilation.

All Fortran 77 source code and include files of the FD package are assumed to be located in a single directory together with all source code and include files of the FORMS and MODEL packages when being compiled and linked. The files with main programs contain, at their ends, Fortran 90 INCLUDE command for all subroutine files required. In this way, each program may simply be compiled and linked as a single file.

All filenames are assumed to be expressed in lowercase.

Fortran 77 source code files have extension '.for'. The corresponding files with specifications of the COMMON blocks have extension '.inc' and are included in the Fortran 77 source code by means of Fortran 90 INCLUDE command.

Compiling and linking programs of package FD

• Copy all files (or at least all *.for and *.inc files) of package FORMS into your working directory. All the files may also be extracted using pkunzip -d forms.zip or tar -xvf forms.tar
  On a computer with a very small memory (less than 16 MB), you may need to decrease array dimension MRAM in the include file ram.inc. On a better computer (more than 16 MB), you may wish to increase array dimension MRAM in the include file ram.inc.
  It is also recommended to compile and link all programs of package FORMS according to the description in forms.htm.
• Copy all files (or at least all *.for and *.inc files) of package MODEL into your working directory. All the files including subdirectories may also be extracted using pkunzip -d model.zip or tar -xvf model.tar
  It is also recommended to compile and link all programs of package MODEL according to the description in model.htm.
• Copy all files (or at least all *.for and *.inc files) of package FD into your working directory. All the files including subdirectories may also be extracted using pkunzip -d fd.zip or tar -xvf fd.tar
• Now you may compile and link following programs of package FD:
  • modfd.for
  • fdmod.for
  • fd2d.for
  • newpar.for
  All necessary subroutine files and include files are included by the Fortran 90 INCLUDE commands located at the end of above listed files containing main programs.
  You may perform the above task by editing Perl script f.pl designed to compile and link a single file, and then running Perl script ffd.pl by typing command
  perl ffd.pl
  If you have no Perl interpreter, it should be available at www.perl.org

Running programs of package FD

Data from standard input *:

Main input data of each program are read from the standard input and mostly consist of a single line containing filenames and at most few numerical parameters.

Description of input data for 'modfd.for'

Calculating effective elastic parameters (harmonic averages of elastic parameters) for 2-D elastic finite differences in models specified by means of the MODEL package.

Description of input data for 'fd2d.for'

Performing 2-D P-SV elastic second-order finite differences.

Description of input data for 'newpar.for'

Modifying the effective elastic parameters (harmonic averages of elastic parameters) for 2-D elastic finite differences.

Brief descriptions of Perl scripts

'fdmax.pl'

'fdpcx.pl'

'fdgifdos.pl'

'fdgiflux.pl'

designed to facilitate creation of wavefield movies (animated GIF).

Example of the history file to run the programs

Example of snapshots for the demo model (1.2 MB)

List of error messages

• Package FORMS
• Package MODEL
• Package FD

File list of package FD

Package FD consists of packages FORMS and MODEL and of the following Fortran 77 and Perl source code and demo files:

(A) Documentation:

fd.htm

This file (main HTML file containing basic description and links the files of this package).

fdver.htm

List of the released versions.

fderr.htm

List of error messages with the links to their descriptions.

(B) Fortran and Perl programs and subroutines:

modfd.for

Program to calculate effective elastic parameters (harmonic averages of elastic parameters) for 2-D elastic finite differences in models specified by means of the MODEL package.

fdmod.for

Program to generate finite-difference effective parameters (harmonic averages of elastic parameters) in 2-D models specified in terms of homogeneous convex polygons (this backward compatibility is included just for test purposes).

fd2d.for

Program for 2-D P-SV elastic second-order finite differences.

fdaux.for

Auxiliary subroutines for FD code, reading and writing input data.

gmtra.for

Subroutine GMTRA of the IBM Scientific Subroutine Package to transpose a general matrix.

newpar.for

Program NEWPAR to modify the effective elastic parameters (harmonic averages of elastic parameters) for 2-D elastic finite differences.

newpar.pl

Perl-script counterpart of 'newpar.for', employing program 'grdcal.for' of package FORMS.

fdmax.pl

Perl script to display the colour saturation of the snapshots.

fdmax.pro

Auxiliary PostScript file to 'fdmax.pl'.

(C) General-purpose scripts and data files

fdpcx.pl

Perl script to convert PostScript snapshots into PCX format using program GhostScript.

fdpcx.bat

MS-DOS batch file to speed up execution of 'fdpcx.pl' using RAM disk.

fdgiflux.pl

Perl script to convert PCX snapshots into GIF (just for Linux).

fdgifdos.pl

Perl script to convert PCX snapshots into GIF (just for MS-DOS).

ffd.pl

Perl script to compile the FD package by means of predefined script 'f.pl' compiling and linking a single Fortran 77 source code file.

snapdiv.cal

snaprot.cal

snap.cal

Input command files for program 'grdcal.for' to transform displacement snapshots into normalized divergence and rotation and, finally, into norm and angle for plotting by program 'grdps.for'.

(D) Demo data:

fd.h

History file with demo data for 2-D FD. It may be executed by command 'perl go.pl fd.h'.

modfd.dat

Input data for package MODEL specifying the demo model for 2-D elastic finite differences.

fdmod.dat

Input data for program 'fdmod.for' specifying the same demo model for 2-D elastic finite differences (just for test purposes).

fdsrc.dat

Source coordinates.

fdrec.dat

Receiver coordinates.

addrec.cal

Script for 'grdcal.for' to overlay snapshots with receiver positions.

modfdps.h

History file to plot the effective elastic parameters calculated by program 'modfd.for' in the demo model.

(E) Comparison with ray-theory seismograms in particular models:

Note that package CRT is required for the comparison. Since the history files for FD require the same data files with receiver and source coordinates as the ray tracing history files, they are located together with referred data files in the respective subdirectories of the CRT package.

rm-fd.h

1-D model RM to test the ray-matrix method.

u2d-fd.h

2-D model UNCONFORMITY (Cormier and Mellen 1984).

(F) Pictures:

fdsnaps.htm

HTML link to the example of snapshots for the demo model.

fdcolor.ps

PostScript diagram showing colours used to display snapshots.

fdcolor.bat

MS-DOS batch file to convert 'fdcolor.ps' into PCX format using program GhostScript.

Acknowledgements

The development of this package has been partially supported by:

• Faculty of Mathematics and Physics, Charles University, Prague.
• Members of consortium 'Seismic Waves in Complex 3-D Structures'.