.TH GSHHG_DP 1gmt "Feb 27 2014" "GMT 4.5.13 (SVN)" "Generic Mapping Tools"
.SH NAME
gshhg_dp \- Line reduction using the Douglas-Peucker algorithm
.SH SYNOPSIS
\fBgshhg_dp\fP \fIinput.b tolerance output.b\fP [\fB\-v\fP]
.SH DESCRIPTION
\fBgshhg_dp\fP reads the binary coastline (GSHHS) or political boundary or river (WDBII) files and
and reduces the complexity of the line by applying the Douglas-Peucker algorithm.  It automatically
handles byte-swabbing between different architectures.
.TP
\fIinput.b\fP
GSHHS or WDBII binary data file as distributed with the GSHHG data supplement.  Any of the
5 standard resolutions (full, high, intermediate, low, crude) can be used.
.TP
\fItolerance\fP
tolerance is maximum mismatch in km.  The larger the value the more reduction will take place.
.TP
\fIoutput.b\fP
The reducted data set.
.SH OPTIONS
.TP
\fB\-v\fP
Reports progress and statistics while running.
.SH EXAMPLES
.sp
To simplify the full GSHHS data set with a custom tolerance of 2 km, try
.sp
\fBgshhg_dp\fP \fIgshhs_f.b 2 gshhs_2km.b\fP
.SH REFERENCES
Douglas, D. H., and T. K. Peucker, Algorithms for the reduction
of the number of points required to represent a digitized line
of its caricature, \fICan. Cartogr., 10\fP, 112-122, 1973.
.SH AUTHOR
This implementation of the D-P algorithm has been kindly provided by
Dr. Gary J. Robinson, Environmental Systems Science Centre,
University of Reading, Reading, UK (gazza@mail.nerc-essc.ac.uk); his
subroutine forms the basis for this program.
.SH "SEE ALSO"
.IR GMT (1),
.IR gshhg (1),
.IR gshhgtograss (1)