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 surfaces and 3-d perspective views in black/white or 24bit
      color.  Linear, log10, and power scaling is supported in additon to 22
      common map projections.  The processing and display routines within
      GMT are completely general and will handle any (x,y) or (x,y,z) data
      as input.

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 for a set
      of points
           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
           grdclip             Limit the z-range in gridded data sets
           grdcontour          Contouring of 2-D gridded data sets
           grdcut              Cut a sub-region from a grd file
           grdedit             Modify header information in a 2-D gridded
      file
           grdfft              Perform operations 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 sets
           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 sets 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
      sets
           grdvolume      Volume calculations from 2-D gridded data sets
           makecpt             Make GMT color palette tables
           mapproject          Transformation of coordinate systems for
      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
           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)
      series
           trend2d             Fits polynomial trends to z = f(x,y) series
           triangulate         Perform optimal Delaunay triangulation and
      gridding
           xyz2grd             Convert an equidistant xyz file to a 2-D grd
      file

SEE ALSO

      Look up the individual man pages for details.  Information is also
      avaiable on the GMT World Wide Web home page
      (http://www.soest.hawaii.edu/gmt)

REFERENCES

      Wessel, P., and W. H. F. Smith, 1999, The Generic Mapping Tools (GMT)
      version 3.2 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
      Mapping Tools Released, EOS Trans., AGU, 76 (33), p. 329.
      Wessel, P., and W. H. F. Smith, 1995, New Version of the Generic
      Mapping Tools Released, http://www.agu.org/eos_elec/95154e.html,
      Copyright 1995 by the American Geophysical Union.
      Wessel, P., and W. H. F. Smith, 1991, Free Software Helps Map and
      Display Data, EOS Trans., AGU, 72 (41), p. 441.