=head1 NAME

Perlsac::rwsac - a module to read and write SAC file.

=head1 DESCRIPTION

This is the module for reading and writing the sac file, defined 
at 'http://ds.iris.edu/files/sac-manual/manual/file_format.html'

=head1 AUTHOR

Hobin Lim

=head1 LICENSE

MIT

=head1 INSTALLATION

Using C<cpan>:

    $ cpan install Perlsac::rwsac

Manual install:

    $ perl Makefile.PL
    $ make
    $ make install

=head1 TUTORIAL

Printing out time and data.

    $ #!/usr/bin/env perl
    $ 
    $ use strict ;
    $ use warnings ;
    $ use Perlsac::rwsac ;
    $ 
    $ my %h = Perlsac::rwsac::rsac("example.sac") ;
    $ 
    $ for (my $n=0; $n<$h{npts}; $n++){
    $     print "$h{t}[$n] $h{d}[$n]\n" ;
    $ }
    $ 

Dividing data by 'depmax' in headers and writing a new sac file.

    $ #!/usr/bin/env perl
    $ 
    $ use strict ;
    $ use warnings ;
    $ use Perlsac::rwsac ;
    $ 
    $ my %h = Perlsac::rwsac::rsac("example.sac") ;
    $ 
    $ for (my $n=0; $n<$h{npts}; $n++){
    $     $h{d}[$n] /= $h{depmax} ;
    $ }
    $ 
    $ &Perlsac::rwsac::wsac("example.sac.div",%h) ;


=cut