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 25 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.

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
 

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
 

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
 

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. These pages are in /usr/share/man/man1/*.1gmt.gz on a Debian system. Information is also available on the GMT home page gmt.soest.hawaii.edu or locally under /usr/share/doc/gmt-doc/gmt_services.html if the gmt-doc package is installed.

REFERENCES

Wessel, P., and W. H. F. Smith, 2001, The Generic Mapping Tools (GMT) version 3.4 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 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: 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.