## 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.