GMT (1) - Linux Manuals

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


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


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 full color. Linear, log10, and power scaling is supported in addition 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.


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.


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 grid files

grd2xyz                Conversion from 2-D grid file to table data

grdblend               Blend several partially over-lapping grid files 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 grid file

grdedit                Modify header information in a 2-D grid file

grdfft         Operate on grid files in the wavenumber (or frequency) domain

grdgradient    Compute directional gradient from grid files

grdhisteq              Histogram equalization for grid files

grdimage               Produce images from 2-D gridded data

grdinfo                Get information about grid files

grdlandmask    Create mask grid file from shoreline data base

grdmask                Reset nodes outside a clip path to a constant

grdmath                Mathematical operations on grid files

grdpaste               Paste together grid files along a common edge

grdproject     Project gridded data onto a new coordinate system

grdreformat    Converting between different grid file formats

grdsample              Resample a 2-D gridded data set onto a new grid

grdtrend               Fits polynomial trends to grid files

grdtrack               Sampling of 2-D data set along 1-D track

grdvector              Plot vector fields from grid files

grdview                3-D perspective imaging of 2-D gridded data

grdvolume              Volume calculations from 2-D gridded data

greenspline    Interpolation using Green's functions for splines in 1-3 dimensions

makecpt                Make 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

ps2raster              Crop and convert PostScript files to raster images, EPS, and PDF

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 (EPS or Sun raster files) on maps

pslegend               Plot legend on maps

psmask         Create overlay to mask out regions on maps

psrose         Plot sector or rose diagrams

psscale                Plot gray scale or color scale on maps

pstext         Plot text strings 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 grid file


Wessel, P., and W. H. F. Smith, 2009, The Generic Mapping Tools (GMT) version 4.5.0 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,, 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.


Look up the individual man pages for more details and full syntax. Run GMT without options to list all GMT programs and to show all installation directories. Information is also available on the GMT home page