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  perspec-
     tive  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  sys-
     tems for table data
          minmax              Find extreme values in data tables
          nearneighbor        Nearest-neighbor gridding scheme
          project             Project data onto lines/great  cir-
     cles
          psbasemap      Create a basemap plot
          psclip              Use polygon files to  define  clip-
     ping paths
          pscoast             Plot  coastlines  and  filled  con-
     tinents 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  seg-
     ments
          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 triangula-
     tion and gridding
          xyz2grd             Convert an equidistant xyz file  to
     a 2-D grd file


SEE ALSO

     Look(l), up(l),  the(l),  individual(l),  man(l),  pages(l),
     for(l),  details.(l) 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.