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 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.

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 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

SEE ALSO¶

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 gmt.soest.hawaii.edu

REFERENCES¶

Wessel, P., and W. H. F. Smith, 2011, The Generic Mapping Tools (GMT) version 4.5.7 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.