3.2 GMT quick reference

Instead of an alphabetical listing, this section contains a summary sorted by program purpose. Also included is a quick summary of the standard command line options and a breakdown of the -J option for each of the 29 map projections available in GMT.

FILTERING OF 1-D AND 2-D DATA
blockmean	L$_2$ estimate ($x,y,z$) data filters/decimators
blockmedian	L$_1$ estimate ($x,y,z$) data filters/decimators
blockmode	Mode estimate ($x,y,z$) data filters/decimators
filter1d	Filter 1-D data (time series)
grdfilter	Filter 2-D data in space domain
PLOTTING OF 1-D and 2-D DATA
grdcontour	Contouring of 2-D gridded data
grdimage	Produce images from 2-D gridded data
grdvector	Plot vector fields from 2-D gridded data
grdview	3-D perspective imaging of 2-D gridded data
psbasemap	Create a basemap frame
psclip	Use polygon files as clipping paths
pscoast	Plot coastlines, filled continents, rivers, and political borders
pscontour	Direct contouring or imaging of xyz data by triangulation
pshistogram	Plot a histogram
psimage	Plot Sun rasterfiles on a map
pslegend	Plot a legend on a map
psmask	Create overlay to mask specified regions of a map
psrose	Plot sector or rose diagrams
psscale	Plot grayscale or colorscale
pstext	Plot textstrings
pswiggle	Draw anomalies along track
psxy	Plot symbols, polygons, and lines in 2-D
psxyz	Plot symbols, polygons, and lines in 3-D

GRIDDING OF (X,Y,Z) TABLE DATA
nearneighbor	Nearest-neighbor gridding scheme
surface	Continuous curvature gridding algorithm
triangulate	Perform optimal Delauney triangulation on xyz data
SAMPLING OF 1-D AND 2-D DATA
grdsample	Resample a 2-D gridded data onto new grid
grdtrack	Sampling of 2-D data along 1-D track
sample1d	Resampling of 1-D data
PROJECTION AND MAP-TRANSFORMATION
grdproject	Transform gridded data to a new coordinate system
mapproject	Transform table data to a new coordinate system
project	Project data onto lines or great circles
INFORMATION
gmtdefaults	List the current default settings
gmtset	Command-line editing of parameters in the .gmtdefaults4 file
grdinfo	Get information about the content of gridded files
minmax	Report extreme values in table data files
MISCELLANEOUS
gmtmath	Reverse Polish Notation (RPN) calculator for table data
makecpt	Create GMT color palette tables
spectrum1d	Compute spectral estimates from time-series
triangulate	Perform optimal Delauney triangulation on xyz data
CONVERT OR EXTRACT SUBSETS OF DATA
gmt2rgb	Convert Sun raster or grd file to red, green, blue component grids
gmtconvert	Convert table data from one format to another
gmtselect	Select table data subsets based on multiple spatial criteria
grd2xyz	Convert 2-D gridded data to table data
grdcut	Cut a sub-region from a gridded file
grdblend	Blend several partially over-lapping grdfiles onto one grid
grdpaste	Paste together gridded files along common edge
grdreformat	Convert from one grid format to another
splitxyz	Split ($x,y,z$) table data into several segments
xyz2grd	Convert table data to 2-D gridded file
DETERMINE TRENDS IN 1-D AND 2-D DATA
fitcircle	Finds best-fitting great or small circles
grdtrend	Fits polynomial trends to gridded files ($z = f(x,y)$)
trend1d	Fits polynomial or Fourier trends to $y = f(x)$ series
trend2d	Fits polynomial trends to $z = f(x,y)$ series
OTHER OPERATIONS ON 2-D GRIDS
grd2cpt	Make color palette table from gridded file
grdclip	Limit the $z$-range in gridded data sets
grdedit	Modify grid header information
grdfft	Operate on gridded files in frequency domain
grdgradient	Compute directional gradients from gridded files
grdhisteq	Histogram equalization for gridded files
grdlandmask	Creates mask gridded file from coastline database
grdmask	Set grid nodes in/outside a clip path to constants
grdmath	Reverse Polish Notation (RPN) calculator for gridded files
grdvolume	Calculate volume under a surface within a contour

STANDARDIZED COMMAND LINE OPTIONS
-B[p$\vert$s]xinfo[/yinfo[/zinfo]][WESNZwesnz+][:.title:] Tickmarks. Each info is
[t]stride[$\pm$phase][u][l$\vert$p][:"label":][:="prefix":][:,"unit":], where l and p apply to $\log_{10}$ axes only, and
type t = {a, A, f, g, i, I}; unit u = {c, C, d, D, h, H, K, k, m, M, o, O, r, R, u, U, y, Y}
The leading p$\vert$s selects primary [Default] or secondary axis items
-H[bf i][n_headers]	ASCII [input] tables have header record[s]
-J (upper case for width, lower case for scale)	Map projection (see below)
-JA $lon_0/lat_0/width$	Lambert azimuthal equal area
-JB $lon_0/lat_0/lat_1/lat_2/width$	Albers conic equal area
-JC $lon_0/lat_0/width$	Cassini cylindrical
-JD $lon_0/lat_0/lat_1/lat_2/width$	Equidistant conic
-JE $lon_0/lat_0/width$	Azimuthal equidistant
-JF $lon_0/lat_0/horizon/width$	Azimuthal Gnomonic
-JG $lon_0/lat_0/width$	Azimuthal orthographic
-JH$lon_0/width$	Hammer equal area
-JI$lon_0/width$	Sinusoidal equal area
-JJ$lon_0/width$	Miller cylindrical
-JKf$lon_0/width$	Eckert IV equal area
-JKs$lon_0/width$	Eckert VI equal area
-JL $lon_0/lat_0/lat_1/lat_2/width$	Lambert conic conformal
-JM$width$ or -JM $lon_0/lat_0/width$	Mercator cylindrical
-JN$lon_0/width$	Robinson
-JOa $lon_0/lat_0/az/width$	Oblique Mercator, 1: origin and azimuth
-JOb $lon_0/lat_0/lon_1/lat_1/width$	Oblique Mercator, 2: two points
-JOc $lon_0/lat_0/lon_p/lat_p/width$	Oblique Mercator, 3: origin and pole
-JP[a$width$[$/origin$]	Polar [azimuthal] ($\theta , r$) (or cylindrical)
-JQ$lon_0/width$	Equidistant cylindrical (Plate Carrée)
-JR$lon_0/width$	Winkel Tripel
-JS $lon_0/lat_0/width$	General stereographic
-JT$lon_0/width$	Transverse Mercator
-JU$zone/width$	Universal Transverse Mercator (UTM)
-JV$lon_0/width$	Van der Grinten
-JW$lon_0/width$	Mollweide
-JX$width$[l$\vert$p$exp\vert$T$\vert$t][/$height$[l$\vert$p$exp\vert$T$\vert$t]][d]	Linear, log$_{10}$, $x^a$-$y^b$, and time
-JY $lon_0/lat_s/width$	General cylindrical equal area
-K	Append more PS later
-O	This is an overlay plot
-P	Select Portrait orientation
-Rwest/east/south/north[/zmin/zmax][r]	Specify Region of interest
-U[/dx/dy/][label]	Plot time-stamp on plot
-V	Run in verbose mode
-X[a]off	Shift plot origin in $x$-direction
-Y[a]off	Shift plot origin in $y$-direction
-b[i$\vert$o][s][ncol]	Select binary input or output
-ccopies	Set number of plot copies [1]
-f[i$\vert$o]colinfo	Set formatting of ASCII input or output
-:	Expect y/x input rather than x/y