Please read ChangeLog for modifications of evalresp above v3.2.38
Please refer to evalresp man pages (evalresp.1) for general information
about evalresp and it's usage.

This directory contains the distribution of evalresp v3.2.38
The historical release notes follow the info on installation.

Since the code is written as ANSI standard C, the standard
BSD 'cc' compiler will not compile it.  I have compiled the code
with the gcc compiler standard SunPro 'cc' compiler (v3.0.1)
under both SunOS and Solaris.  The code is also known to compile
on the following machines:

Intel machines (under both LINUX and FreeBSD Unix)
HP-UX workstations
SGI workstations

As of v3.2.20, the code will compile under Microsoft Windows 95/98/NT
using Borland C++ 5.02 or Microsoft Visual C++ 6.0.

Any ANSI standard C compiler should work with the code.

This distribution is fairly self contained.  Because of the variety
of machines that the code is distrubuted on now, an executable is
no longer included with the distribution.

To build the executable on a Unix-based machine, type the following
commands from the 'evalresp' directory:

./configure
make

The configure script should set up a Makefile that is appropriate
for your available resources.  Once that Makefile is built, simply
typing "make" will build the "libevresp.a" library and build an
executable called "evalresp".

To build the executable on a Microsoft Windows-based machine, use
one of the following make files:
makefile.bor  -  for Borland C++
makefile.ms   -  for Microsoft Visual C++
The file "evalresp.ide" is a project file for use with the Borland
C++ v5.02 graphical IDE.

The "evresp" C function can be called from within your own C code
to calculate responses from RESP files, or the "evresp_" function
can be called from a FORTRAN program.  A simple example of calling
"evresp_" from a FORTRAN program is available in the "evtest.f" file.


tjm@iris.washington.edu
14 March, 1997
Modified
i.dricker@isti.com
17 July, 2001
Modified (MS Windows port) 
e.thomas@isti.com
28 August, 2001

------------------ Release Notes (old) ------------------------
[See the "ChangeLog" file for more recent release notes]
version 3.2.24 ( Apr 5, 2004) - IGD
Added two configuration option:
 --enable-delay Use estimated delay in phase computation
 --enable-phase-unwrap Unwrap phase

In order to enable those options evalresp should be configured like:
./configure --enable-delay --enable-phase-unwrap

version 3.2.23 ( Mar 19, 2004) - SBH
Added support for SHAPE compatible RESP files. When parsing lines that are valid
RESP format, but unexpected, evalresp now skips to the next line.
Added support for blank lines within and at the end of a RESP file.

version 2.3.22 (21-Oct-2003)
FIXED: evaluation of the response for an IIR filter. Versions before 
2.3.20 computed IIR PZ incorrectly. Versions 3.2.20-21 computed amplitude
of the filter properly, while PHASE was improperly multiplied by (-1),
mirrored aross y = 0. This release fixes the problem.

ADDED: Interpolation of blockette 55 (to enable this feature, the program
should be compiled with -DB55_INTRPL compilation flag, which is not set
by default). This feature is experimaental and not recommended for the 
general use. 

version 2.3.21 (21-May-2002)
Added a partial support for generic response blockette. Partial means that
if such blockette is found, evalresp ignores the blockette, prints a warning
and continues execution. Previous versions considered the generic response 
blockette to be offensive and terminated the processing of the response

version 3.2.20 (28-August-2001)
Code ported to work with Microsoft Windows-based compilers.  Functionality
should be unchanged.

version 3.2.19 (30-July-2001)
1) A bug which forced evalresp to compute incorrect group delays has been fixed.
2) A computation of decimation is removed from evalresp.
To compute decimation evalresp relies upon the fields 7 and 8 of SEED blockette 57.
However, the use of these fields are inconsistant among digitizers and
SEED builders.
3) A mechinism of selecting files for processing from the working directory for some
Solaris computers was shown to be unrelible in at least a single case in all versions
below 3.2.19. This mechanism was modified. As a trade-off the orcessing of a single RESP
file in versions 3.2.19 and above is slower by about one second than in the previous
versions.

Version 3.2.18
Presure data support is included

version 3.2.17 Notes:

Modifications from version 3.2.16 to version 3.2.17 are conduced
by  Instrumental Software Technologies, Inc. (www.isti.com)
Modifications have been requested by IRIS DMC.

These modifications include:

(1)    Version  3.2.17  supports  IIR digital filters in coeffi­
       cients format with a non-zero phase  shift.   IIR  coeffi­
       cients  for a single stage must fit in a single blockette.
       The algorithm was adopted from the FORTRAN code provided by
       B. Hutt (hutt@asl.cr.usgs.gov).

(2)     Version 3.2.17 and above supports generic response block­
       ette  (SEED blockettes 55).  Generic response blockette is
       a list of phases and amplitudes computed  for  the  prese­
       lected  set  of frequencies. This filter type is supported
       only if the response input file contains  blockette(s)  55
       as a stage 1 and possibly channel sensitivity blockette as
       a stage 0.  If generic response blockette is recognized in
       the  input,  evalresp  ignores  the user-defined frequency
       sampling from the command line. The ouput, therefore, con­
       tains responses for only those frequencies which have been 			
       defined in the generic response blockette.

(3)    The source code is cleaned; all unused variables are removed

(4)    The man pages are modified to reflect the current version of 
       the evalresp. 
	 
version 3.0 to version 3.2:

(1) Error handling improved.  In version 3.0, if the end of the file was
    encountered while searching for the next response, an extraneous error
    message was often printed to the effect of

    EVRESP ERROR: get_line (parsing blockette [050]); unexpected fld number
                    fld_xpt=F16, fld_found=F03, skipping to next response now

    when, in fact, a message should have appeared that this sta-chan-net tuple
    was not found.  In version 3.1 so that the message that now appears is

    WARNING: no response found for STA=ANMO,CHAN=SHZ,DATE=1994,122,00:00:00

(2) Error messages improved.  In version 3.0, when an error was printed, there
    was no information in the error input as to where in the process the error
    occurred.  While this may have been apparent if only a few files were being
    processed, it was not at all obvious where the error occurred if a large
    number of sta-cha-net files were being processed.  To improve this,

    (a) The name of the file that is being parsed has been added to all error
        messages.  For example, if an error occurred while parsing the file
        response information for the ANMO LHZ channel as reported by the SRO
        network because the line containing the network code was missing,
        evalresp v3.0 would have reported

        EVRESP ERROR: get_line; blkt and fld numbers do not match expected values
                blkt_xpt=B050, blkt_found=B052; fld_xpt=F16, fld_found=F04, skipping
                to next response now

        whereas evalresp v3.1 reports (for the same parsing error)

        EVRESP ERROR (RESP.SR.ANMO.LHZ): get_line; blkt and fld numbers do not match
            expected values blkt_xpt=B050, blkt_found=B052; fld_xpt=F16, fld_found=F04,
            skipping to next response now

(3) Changes were made to make the code more portable.  Although the code was 'test compiled'
    on a DEC ALPHA and on SUNs running SUNOS 4.1.3, problems were encountered when porting
    the code to the HPUX OS.  To make the code more portable, the following changes were made.

    (a) The buffer length for the output of the child process that lists the directory
        to find matching files has been set to zero using 'setbuf' rather than 'setlinebuf'.
        Again, this change was made so that the code would be 'ANSI standard'.

    (b) The calls to 'getwd()' have been replaced with calls to 'getcwd()', which seems to
        be more 'standard' than 'getwd()', as it exists as part of the SUN OS, the DEC OS,
        and the HPUX OS

    (c) Finally, the 're_comp()' and 're_exec()' routines, which are not part of the ANSI
        standard C standard library, do not seem to be supported under the HPUX OS (although
        both the DEC Unix OS and SUN OS do support them).  As a result, code is included in this
        distribution for a set of routines taken from Henry Spencer's 'regexp' utility that
        implement 'regular expression' pattern matching in the style of the UNIX utility
        'egrep'.  The new files are:  'regexp.c', 'regsub.c', 'regerror.c', 'regexp.h', and
        'regmagic.h'.  The 'main' routines of this package (which are used in place of
        're_comp()' and 're_exec()') are called 'regcomp()' and 'regexec()', respectively.
        The inclusion of these files should result in a more portable distribution, since the
        only function calls made in this package are to ANSI standard library functions.

        This package was obtained via anonymous ftp from the University of Toronto, and minimal
        changes have been made to make it more compatible with 'evalresp'.  Specifically, a few
        '#include' directives were removed that were not needed for the routines to be used as
        a 'stand-alone' package and several redeclarations of the 'strchr()' standard library
        function in the file 'regexp.c' were replaced with an '#include <string.h>' statement
        at the beginning of that code.  The following statements are taken from the 'README'
        file for this package and are included to give credit where credit is due:

                 This is a nearly-public-domain reimplementation of the V8 regexp(3) package.
                 It gives C programs the ability to use egrep-style regular expressions, and
                 does it in a much cleaner fashion than the analogous routines in SysV.

                      Copyright (c) 1986 by University of Toronto.
                      Written by Henry Spencer.  Not derived from licensed software.

                 Permission is granted to anyone to use this software for any
                 purpose on any computer system, and to redistribute it freely,
                 subject to the following restrictions:

                  1. The author is not responsible for the consequences of use of
                         this software, no matter how awful, even if they arise
                         from defects in it.

                  2. The origin of this software must not be misrepresented, either
                         by explicit claim or by omission.

                  3. Altered versions must be plainly marked as such, and must not
                             be misrepresented as being the original software.


                 This implementation is *NOT* AT&T/Bell code, and is not derived from licensed
                 software.  Even though U of T is a V8 licensee.  This software is based on
                 a V8 manual page sent to me by Dennis Ritchie (the manual page enclosed
                 here is a complete rewrite and hence is not covered by AT&T copyright).
                 The software was nearly complete at the time of arrival of our V8 tape.
                 I haven't even looked at V8 yet, although a friend elsewhere at U of T has
                 been kind enough to run a few test programs using the V8 regexp(3) to resolve
                 a few fine points.  I admit to some familiarity with regular-expression
                 implementations of the past, but the only one that this code traces any
                 ancestry to is the one published in Kernighan & Plauger (from which this
                 one draws ideas but not code).

(4) Bug fixed for handling of FIR filters.  If a FIR filter was renormalized in version 3.0,
    the normalization constant for that filter was not changed to compensate.  As a result the
    response of channels with FIR filter stages that were renormalized to a constant frequency
    are not correct in evalresp v3.0.

(5) A fourth option was added to the 'output units'.  If this option is chosen, then
    the response that is returned to the user will be in terms of the input units per output
    units, regardless of the unit themselves.  This was done to allow responses to be calculated
    for magnetometers, strain meters, and pressure, or temperature sensors, where it really
    doesn't make sense to talk about the 'units' in terms of displacement, velocity, or
    acceleration, but the user would still like to see the frequency response of the instrument.
    If the flag '-u def' is chosen, then evalresp will calculate the response spectra for these
    types of instruments, if any other units are specified, these types of instruments will
    be skipped as having 'unrecognized' types of units (i.e. units that cannot be converted
    into the type of units that the user requested).

(6) many bugs that were reported by users in the way that evalresp went about
    evaluation of responses have been fixed.  Some of these problems were due
    to the fact that evalresp expected the blockettes to appear in a certain
    order (when, in fact, the SEED format did not), while others had to do with
    legal SEED constructs that had not been seen yet (and, as a result, where not
    tested before the release of version 3.0).  In some cases, the response values
    calculated by evalresp were found to be in error by several percent, while in
    other cases evalresp failed to correctly parse legal filter sequences.  In each
    case, the bug reports were traced and fixes were made.  Thanks to the beta
    test group for all of the work that they put in on this.

(7) a "-stdio" command line flag has been added that allows evalresp to be
    placed into a "pipeline".  In fact, this functionality is already in use
    here at the DMC in calculation of responses from a set of "stage response
    files".  When the "-stdio" command line flag is set, the program takes input
    (which is assumed to be from a RESP file or a series of RESP files) from stdin
    and returns the calculated responses to stdout.  The format is slightly
    different than the format used to output the calculated responses when the
    output is to a file, since there are multiple station-channel-netword tuple's
    responses being returned to stdout.  Basically, the program adds a short
    header to the stdout stream so that the responses can be separated later by
    whatever application program will be receiving the output from evalresp.
    As always, the verbose output and error output both appear on stderr, so they
    will not appear mixed in with the calculated responses.

(8) a new command line option was defined to allow users to evaluate the response
    for a subset of the overall response for a channel.  This option allows users
    to specify the stage (or range of stages) that they wish to evaluate the
    response for.  If response stages are skipped in this process, then evalresp
    will not compare the calculated overall sensitivity with the reported
    overall sensitivity in the RESP file, since the calculated response leaves
    out parts of the response file.  This option is useful for looking at the
    effect of individual response stages on the overall response (and for checking
    for problems with a stage that is under construction).

tjm@iris.washington.edu
14 March, 1997
