# Modules (Classic Mode)

Note

Looking for the modern mode modules like `begin` and `figure`? See the equivalent page for modern mode.

This is a list of all GMT “classic mode” core and supplemental modules and their uses, as well as some utility scripts. These modules are fully compatible with GMT 4 and 5. All modules are requested via a call to the gmt program.

## Program

- gmt

## Core Modules

- batch

- blockmean

- blockmedian

- blockmode

- dimfilter

- docs

- filter1d

- fitcircle

- gmt2kml

- gmtbinstats

- gmtconnect

- gmtconvert

- gmtdefaults

- grdgdal

- gmtget

- gmtinfo

- gmtlogo

- gmtmath

- gmtregress

- gmtselect

- gmtset

- gmtsimplify

- gmtspatial

- gmtsplit

- gmtvector

- gmtwhich

- grd2cpt

- grd2kml

- grd2xyz

- grdblend

- grdclip

- grdcontour

- grdconvert

- grdcut

- grdedit

- grdfft

- grdfill

- grdfilter

- grdgradient

- grdhisteq

- grdimage

- grdinfo

- grdinterpolate

- grdlandmask

- grdmask

- grdmath

- grdmix

- grdpaste

- grdproject

- grdsample

- grdselect

- grdtrack

- grdtrend

- grdvector

- grdview

- grdvolume

- greenspline

- kml2gmt

- makecpt

- mapproject

- nearneighbor

- project

- psbasemap

- psclip

- pscoast

- pscontour

- psconvert

- psevents

- pshistogram

- psimage

- pslegend

- psmask

- psrose

- psscale

- pssolar

- psternary

- pstext

- pswiggle

- psxy

- psxyz

- sample1d

- spectrum1d

- sph2grd

- sphdistance

- sphinterpolate

- sphtriangulate

- surface

- trend1d

- trend2d

- triangulate

- xyz2grd

## Supplemental Modules

- earthtide

- gpsgridder

- psvelo

- fzanalyzer

- fzblender

- fzinformer

- fzmapper

- fzmodeler

- fzprofiler

- mlconverter

- gshhg

- img2grd

- mgd77convert

- mgd77header

- mgd77info

- mgd77list

- mgd77magref

- mgd77manage

- mgd77path

- mgd77sniffer

- mgd77track

- gmtflexure

- gmtgravmag3d

- gravfft

- gravprisms

- grdflexure

- grdgravmag3d

- grdredpol

- grdseamount

- talwani2d

- talwani3d

- pssegy

- pssegyz

- segy2grd

- pscoupe

- psmeca

- pspolar

- pssac

- backtracker

- gmtpmodeler

- grdpmodeler

- grdrotater

- grdspotter

- hotspotter

- originater

- polespotter

- rotconverter

- rotsmoother

- grdbarb

- psbarb

- x2sys_binlist

- x2sys_cross

- x2sys_datalist

- x2sys_get

- x2sys_init

- x2sys_list

- x2sys_merge

- x2sys_put

- x2sys_report

- x2sys_solve

## Utility Scripts

- gmt-config

- gmt5syntax

- gmt_shell_functions.sh

- gmtswitch

- isogmt

- img2google

## Plotting

gmtlogo | Plot the GMT logo
grdcontour | Make contour map using a grid
grdimage | Project and plot grids or images
grdvector | Plot vector field from two component grids
grdview | Create 3-D perspective image or surface mesh from a grid
psbasemap | Plot base maps and frames
psclip | Initialize or terminate polygonal clip paths
pscoast | Plot continents, countries, shorelines, rivers, and borders
pscontour | Contour table data by direct triangulation
psevents | Plot event symbols, lines, polygons and labels for one moment in time
pshistogram | Calculate and plot histograms
psimage | Plot raster or EPS images
pslegend | Plot a legend
psmask | Clip or mask map areas with no data table coverage
psrose | Plot a polar histogram (rose, sector, windrose diagrams)
psscale | Plot gray scale or color scale bar
pssolar | Plot day-light terminators and other sunlight parameters
psternary | Plot data on ternary diagrams
pstext | Plot or typeset text
pswiggle | Plot z = f(x,y) anomalies along tracks
psxy | Plot lines, polygons, and symbols in 2-D
psxyz | Plot lines, polygons, and symbols in 3-D

## Filtering

blockmean | Block average (x,y,z) data tables by mean estimation
blockmedian | Block average (x,y,z) data tables by median estimation
blockmode | Block average (x,y,z) data tables by mode estimation
dimfilter | Directional filtering of grids in the space domain
filter1d | Time domain filtering of 1-D data tables
grdfilter | Filter a grid in the space (or time) domain

## Gridding

greenspline | Interpolate using Green’s functions for splines in 1-3 dimensions
nearneighbor | Grid table data using a "Nearest neighbor" algorithm
sphinterpolate | Spherical gridding in tension of data on a sphere
surface | Grid table data using adjustable tension continuous curvature splines
triangulate | Delaunay triangulation or Voronoi partitioning and gridding of Cartesian data
grdinterpolate | Interpolate a 3-D cube, 2-D grids or 1-D series from a 3-D data cube or stack of 2-D grids

## Sampling of 1-D and 2-D data

gmtsimplify | Line reduction using the Douglas-Peucker algorithm
grdsample | Resample a grid onto a new lattice
grdtrack | Sample one or more grids at specified locations
sample1d | Resample 1-D table data using splines

## Projection and map-transformation

grdproject | Forward and inverse map transformation of grids
mapproject | Forward and inverse map transformations, datum conversions and geodesy
project | Project data onto lines or great circles, or generate tracks

## Information retrieval

gmtdefaults | List current GMT default settings
gmtget | Get individual GMT default settings or download data sets
gmtinfo | Get information about data tables
gmtset | Change individual GMT default settings
grdinfo | Extract information from 2-D grids or 3-D cubes
grdselect | Make selections or determine common regions from 2-D grids, images or 3-D cubes

## Mathematical operations on tables or grids

gmtmath | Reverse Polish Notation (RPN) calculator for data tables
makecpt | Make GMT color palette tables
spectrum1d | Compute auto- [and cross-] spectra from one [or two] time series
sph2grd | Compute grid from spherical harmonic coefficients
sphdistance | Create Voronoi distance, node, or natural nearest-neighbor grid on a sphere
sphtriangulate | Delaunay or Voronoi construction of spherical data

## Convert or extract subsets of data

gmtbinstats | Bin spatial data and determine statistics per bin
gmtconnect | Connect individual lines whose end points match within tolerance
gmtconvert | Convert, paste, or extract columns from data tables
gmtselect | Select data table subsets based on multiple spatial criteria
gmtspatial | Geospatial operations on points, lines and polygons
gmtsplit | Split xyz[dh] data tables into individual segments
gmtvector | Operations on Cartesian vectors in 2-D and 3-D
grd2kml | Create KML image quadtree from single grid
grd2xyz | Convert grid to data table
grdblend | Blend several partially overlapping grids into one larger grid
grdconvert | Convert between different grid formats
grdcut | Extract subregion from a grid or image or a slice from a cube
grdpaste | Join two grids along their common edge
xyz2grd | Convert data table to a grid

## Trends in 1-D and 2-D data

fitcircle | Find mean position and great [or small] circle fit to points on sphere
gmtregress | Linear regression of 1-D data sets
grdtrend | Fit trend surface to grids and compute residuals
trend1d | Fit [weighted] [robust] polynomial/Fourier model for y = f(x) to xy[w] data
trend2d | Fit [weighted] [robust] polynomial for z = f(x,y) to xyz[w] data

## Grid operations

grd2cpt | Make linear or histogram-equalized color palette table from grid
grdclip | Clip the range of grid values
grdedit | Modify header or content of a grid
grdfft | Mathematical operations on grids in the spectral domain
grdfill | Interpolate across holes in a grid
grdgradient | Compute directional gradients from a grid
grdhisteq | Perform histogram equalization for a grid
grdlandmask | Create a "wet-dry" mask grid from shoreline data base
grdmask | Create mask grid from polygons or point coverage
grdmath | Reverse Polish Notation (RPN) calculator for grids (element by element)
grdmix | Blending and transforming grids and images
grdvolume | Calculate grid volume and area constrained by a contour

## Miscellaneous

batch | Automate batch job processing
docs | Show HTML documentation of specified module
gmt2kml | Convert GMT data table to Google Earth KML file
grdgdal | Execute GDAL raster programs from GMT
gmtwhich | Find full path to specified files
kml2gmt | Extract GMT table data from Google Earth KML files
psconvert | Convert [E]PS file(s) to other formats using Ghostscript

## geodesy

earthtide | Compute grids or time-series of solid Earth tides
gpsgridder | Interpolate GPS velocities using Green’s functions for elastic deformation
psvelo | Plot velocity vectors, crosses, anisotropy bars and wedges

## GSFML

fzanalyzer | Analysis of fracture zones using crossing profiles
fzblender | Produce a smooth blended FZ trace
fzinformer | Bash script to plot statistical information related to fracture zones
fzmapper | Bash script to plot fracture zone cross-profiles on a Mercator map
fzmodeler | Bash script to build fracture zone cross-profile model
fzprofiler | Bash script to plot fracture zone cross-profiles
mlconverter | Convert chrons to ages using selected magnetic timescale

## GSHHG

gshhg | Extract data tables from binary GSHHG or WDBII data files

## IMG

img2grd | Extract a subset from an img file in Mercator or Geographic format

## MGD77

mgd77convert | Convert MGD77 data to other formats
mgd77header | Create MGD77 headers from A77 files
mgd77info | Extract information about MGD77 files
mgd77list | Extract data from MGD77 files
mgd77magref | Evaluate the IGRF or CM4 magnetic field models
mgd77manage | Manage the content of MGD77+ files
mgd77path | Return paths to MGD77 cruises and directories
mgd77sniffer | Along-track quality control of MGD77 cruises
mgd77track | Plot track-lines of MGD77 cruises

## potential

gmtflexure | Compute flexural deformation of 2-D loads, forces, and bending moments
gmtgravmag3d | Compute the gravity/magnetic anomaly of a 3-D body by the method of Okabe
gravfft | Spectral calculations of gravity, isostasy, admittance, and coherence for grids
gravprisms | Compute geopotential anomalies over 3-D vertical prisms
grdflexure | Compute flexural deformation of 3-D surfaces for various rheologies
grdgravmag3d | Computes the gravity effect of one (or two) grids by the method of Okabe
grdredpol | Compute the Continuous Reduction To the Pole, AKA differential RTP
grdseamount | Create synthetic seamounts (Gaussian, parabolic, polynomial, cone or disc; circular or elliptical)
talwani2d | Compute geopotential anomalies over 2-D bodies by the method of Talwani
talwani3d | Compute geopotential anomalies over 3-D bodies by the method of Talwani

## SEGY

pssegyz | Plot a SEGY file in 3-D
pssegy | Plot a SEGY file in 2-D
segy2grd | Converting SEGY data to a grid

## seis

pscoupe | Plot cross-sections of focal mechanisms
psmeca | Plot focal mechanisms
pspolar | Plot polarities on the lower hemisphere of the focal sphere
pssac | Plot seismograms in SAC format
grdshake | Compute Peak Ground Acceleration/Velocity and Intensity
grdvs30 | Convert topographic slope to Vs30 velocities

## spotter

backtracker | Generate forward and backward flowlines and hotspot tracks
gmtpmodeler | Evaluate a plate motion model at given locations
grdpmodeler | Evaluate a plate motion model on a geographic grid
grdrotater | Finite rotation reconstruction of geographic grid
grdspotter | Create CVA grid from a gravity or topography grid
hotspotter | Create CVA grid from seamount locations
originater | Associate seamounts with nearest hotspot point sources
polespotter | Find stage poles given fracture zones and abyssal hills
rotconverter | Manipulate total reconstruction and stage rotations
rotsmoother | Get mean rotations and covariance matrices from set of finite rotations

## windbarbs

psbarb | Plot wind barbs in 2-D and 3-D
grdbarb | Plot wind barb field from two component grids

## x2sys

x2sys_binlist | Create bin index listing from track data files
x2sys_cross | Calculate crossovers between track data files
x2sys_datalist | Extract content of track data files
x2sys_get | Get track listing from track index database
x2sys_init | Initialize a new x2sys track database
x2sys_list | Extract subset from crossover data base
x2sys_merge | Merge an updated COEs table (smaller) into the main table (bigger)
x2sys_put | Update track index database from track bin file
x2sys_report | Report statistics from crossover data base
x2sys_solve | Determine least-squares systematic correction from crossovers