
       *** INTRODUCTION TO PROGRAMS FPFIT, FPPLOT AND FPPAGE ***

CONGRATULATIONS!  You are now the proud owner of software for the calculation
and graphic display of earthquake fault-plane solutions. This brief written
introduction is intended to accompany the source and executable code
plus test data files sufficient to bring up this software on a PC computer.  
The programs - FPFIT, FPPLOT, and FPPAGE - are documented in the separate report:

   FPFIT, FPPLOT AND FPPAGE: FORTRAN COMPUTER PROGRAMS FOR CALCULATING
          AND DISPLAYING EARTHQUAKE FAULT-PLANE SOLUTIONS

                               BY

                P. REASENBERG  AND  D. OPPENHEIMER

        U.S. GEOLOGICAL SURVEY OPEN-FILE REPORT NO. 85-739


If you do not already have a copy of Open-File Report 85-739, please obtain a
copy from:

David Oppenheimer
U.S.G.S
345 Middlefield Rd - MS 977
Menlo Park, CA 94025
U.S.A.
415-329-4792
oppen@alum.wr.usgs.gov

The Open-File Report is somewhat outdated, but the theory behind the code is basically
unchanged. The main differences between the code described in the Open-File
Report and enclosed version is that 
1) FPFIT is interactively driven.  All the options are set by three-letter 
   commands which are described with on-line documentation.  
2) FPFIT now does a better job representing the 90% confidence regions.  
3) The alphabetic letter codes on the end of the summary card are no longer 
   produced.
4) A "C" is output in column 128 if the solution fails to converge during the 
   fine search range.  By conversion, we mean that the best solution was found 
   on the edge of the fine search grid instead of the center of the search 
   range as expected.  This flag is almost always produced on multiple 
   solutions.  Generally this means that if the solution had been allowed to 
   continue searching for the absolute minimum, it would have been identical
   to the minimum reported for a multiple.  Examination of the 90% confidence
   region also indicates if the non-converging solution is approaching the
   solution of another multiple.
5) The "*" which indicates a multiple solution is now output in column 129.
6) The code prioritizes the choice of magnitude posted on the HYPO71 format
   if the input format is Hypoinverse.  Priority is ML using the USGS location,
   ML from UC Berkeley, Coda from USGS, and Amplitude from USGS.


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Although this program has been used by the USGS, no warranty, expressed
or implied, is made by the USGS or the United States Government as to
the accuracy and functioning of the program and related program
material nor shall the fact of distribution constitute any such
warranty, and no responsibility is assumed by the USGS in connection
therewith.
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                    DESCRIPTION OF FILES

	(substitute ".F" for ".FOR" for Unix versions)

FILE                  CONTENTS
--------------------------------------------------------------------------------
FPFIT.FOR             FORTRAN source, Version 1.2 

FPPLOT.FOR            FORTRAN source, Version 1.2

FPPAGE.FOR            FORTRAN source, Version 1.2

PTPLOT.FOR            FORTRAN source - plots P- and T-axes on stereonet with mean axes 
                                       and 90% confidence region of distribution.

MKTABLE.FOR           FORTRAN source - converts .fps output into readable table

EXAMPLE.LST           example of a HYPOINVERSE archive output 
                      file for use as data input to FPFIT

EXAMPLE.INP           example of an input control file for FPFIT

EXAMPLE.OUT           output file summarizing a run of FPFIT using the above
                      two input files 

EXAMPLE.POL           output file from the same run of FPFIT for use as input
                      to the graphics programs FPPLOT and FPPAGE

EXAMPLE.FPS           output of the same run of FPFIT listing the fault plane
                      solutions obtained.


1.  Test program FPFIT. The first thing that will happen is that a prompt
will be given.  Type "hel" or "mor" for a list of commands.  Type
"@EXAMPLE.INP" to read control file, and then type "fps" to compute
three sample fault-plane solutions.  When prompt returns, type "sto" to
stop the program
        
          EXAMPLE.OUT      summary of the run parameters and a compilation of
                           statistics resulting from it. 

          EXAMPLE.FPS      extended hypocenter summary cards showing solution
                           parameters for all fault plane solutions determined. 

          EXAMPLE.POL      intermediate file for use as input to programs
                           FPPLOT and FPPAGE. 

These three files should be identical to the like-named "EXAMPLE" files
provided.

3.  Test the interactive program FPPLOT and answer the prompt for filename
with the response: "EXAMPLE.POL".  Answer the other prompts as you please.

4.  Test the interactive program FPPAGE and answer the prompt for filename
with the response: "EXAMPLE.POL".  Answer the other prompts as you please.

5.  Test PTPLOT the same way.  This program is not described in the Open-
File Report. It reads the ".FPS" files and generates scatter plots of
the P & T axes with the distribution mean and 95% confidence limits calculated
through the use of Bingham statistics [see Bingham, C., An antipodally 
symmetric distribution on the sphere, Ann. Statist., 6, 1201-1225, 1974].

Good luck.
