## NAME

           GMT  -  The  Generic Mapping Tools data processing and display software
           package

## INTRODUCTION

           GMT is a collection of public-domain Unix  tools  that  allows  you  to
           manipulate x,y and x,y,z data sets (filtering, trend fitting, gridding,
           projecting, etc.)  and produce PostScript  illustrations  ranging  from
           simple  x-y  plots,  via contour maps, to artificially illuminated sur-
           faces and 3-d perspective views in black/white or 24bit color.  Linear,
           log10, and power scaling is supported in addition to 25 common map pro-
           jections. The processing and display routines within GMT are completely
           general and will handle any (x,y) or (x,y,z) data as input.

## SYNOPSIS

           GMT is also a wrapper script that can start any of the programs:

           GMT module module-options

           where  module  is  the  name of a GMT program and the options are those
           that pertain to that particular program.

## GMT OVERVIEW

                   The following is a summary of all the  programs  supplied  with
           GMT and a very short description of their purpose. Detailed information
           about each program can be found in the separate manual pages.

           blockmean L2 (x,y,z) data filter/decimator
           blockmedian L1 (x,y,z) data filter/decimator
           blockmode Mode (x,y,z) data filter/decimator
           filter1d Filter 1-D data sets (time series)
           fitcircle Finds the best-fitting great circle to a set
                                   of points
           gmt2rgb Convert Sun rasterfile or grid to r, g, b
                                   grids
           gmtconvert Convert between ASCII and binary 1-D tables
           gmtdefaults List the current default settings
           gmtmath Mathematical operations on data tables
           gmtset Set individual default parameters
           gmtselect Extract data subsets based on spatial
                                   criteria
           grdfilter Filter 2-D data sets in the space domain
           grd2cpt Make a color palette table from a grdfile
           grd2xyz Conversion from 2-D gridded file to table
                                   data
           grdblend Blend several partially over-lapping grdfiles
                                   onto one grid
           grdclip Limit the z-range in gridded data
           grdcontour Contouring of 2-D gridded data
           grdcut Cut a sub-region from a grd file
           grdedit Modify header information in a 2-D gridded
                                   file
           grdfft Operate on grdfiles in the frequency domain
           grdgradient Compute directional gradient from grdfiles
           grdhisteq Histogram equalization for grdfiles
           grdimage Produce images from 2-D gridded data
           grdinfo Get information about grd files
           grdlandmask Create mask grdfile from shoreline data base
           grdmask Reset nodes outside a clip path to a constant
           grdmath Mathematical operations on grdfiles
           grdpaste Paste together grdfiles along a common edge
           grdproject Project gridded data onto a new coordinate
                                   system
           grdreformat Converting between different grdfile formats
           grdsample Resample a 2-D gridded data set onto a new
                                   grid
           grdtrend Fits polynomial trends to grdfiles
           grdtrack Sampling of 2-D data set along 1-D track
           grdvector Plot vector fields from grdfiles
           grdview 3-D perspective imaging of 2-D gridded data
           grdvolume Volume calculations from 2-D gridded data
           makecpt Make GMT color palette tables
           mapproject Forward or inverse map projections of table
                                   data
           minmax Find extreme values in data tables
           nearneighbor Nearest-neighbor gridding scheme
           project Project data onto lines/great circles
           psbasemap Create a basemap plot
           psclip Use polygon files to define clipping paths
           pscoast Plot coastlines and filled continents on maps
           pscontour Contour xyz-data by triangulation
           pshistogram Plot a histogram
           psimage Plot images (Sun rasterfiles) on maps
           pslegend Plot legend on maps
           psmask Create overlay to mask out regions on maps
           psrose Plot sector or rose diagrams
           psscale Plot grayscale or colorscale on maps
           pstext Plot textstrings on maps
           pswiggle Draw time-series along track on maps
           psxy Plot symbols, polygons, and lines on maps
           psxyz Plot symbols, polygons, and lines in 3-D
           sample1d Resampling of 1-D table data sets
           spectrum1d Compute various spectral estimates from time-
                                   series
           splitxyz Split xyz-files into several segments
           surface A continuous curvature gridding algorithm
           trend1d Fits polynomial or Fourier trends to y = f(x)
                                   data
           trend2d Fits polynomial trends to z = f(x,y) data
           triangulate Perform optimal Delaunay triangulation and
                                   gridding
           xyz2grd Convert equidistant xyz data to a 2-D grd
                                   file

## SEE ALSO

           Look up the individual man pages for details. By default,  these  pages
           are  in  $GMTHOME/man/manl,  depending  on  your installation settings.
           Information is also available on the GMT home page gmt.soest.hawaii.edu
           or locally under $GMTHOME/www/gmt/gmt_services.html

## REFERENCES

           Wessel,  P.,  and W. H. F. Smith, 2004, The Generic Mapping Tools (GMT)
           version 4 Technical Reference & Cookbook, SOEST/NOAA.
           Wessel, P., and W. H. F. Smith, 1998, New, Improved Version of  Generic
           Mapping Tools Released, EOS Trans., AGU, 79 (47), p. 579.
           Wessel,  P.,  and W. H. F. Smith, 1995, New Version of the Generic Map-
           ping Tools Released, EOS Trans., AGU, 76 (33), p. 329.
           Wessel, P., and W. H. F. Smith, 1995, New Version of the  Generic  Map-
           ping Tools Released, http: American Geophysical Union.
           Wessel,  P., and W. H. F. Smith, 1991, Free Software Helps Map and Dis-
           play Data, EOS Trans., AGU, 72 (41), p. 441.

    GMT4.0                            1 Oct 2004                            GMT(l)