pscoast − To plot land-masses, water-masses, coastlines, borders, and rivers


pscoast −Jparameters −Rwest/east/south/north[r] [ −Amin_area[/min_level/max_level] ] [ −B[p|s]parameters ] [ −Cfill ] [ −Dresolution ] [ −Eazimuth/elevation ] [ −Gfill ] [ −Iriver[/pen] ] [ −Jz|Zparameters ] [ −K ] [ −L[f][x]lon0/lat0[/slon]/slat/length[m|n|k][:label:just][+ppen][+ffill] ] ] [ −O ] [ −M[flag] ] [ −Nborder[/pen] ] [ −O ] [ −P ] [ −Q ] [ −Sfill ] [ −T[f|m][x]lon0/lat0/size[/info][:w,e,s,n:][+gint[/mint]] ] [ −U[/dx/dy/][label] ] [ −V ] [ −Wpen ] [ −X[a|c|r][x-shift[u]] ] [ −Y[a|c|r][y-shift[u]] ] [ −Zzlevel ] [ −ccopies ] [ −bo[s|S|d|D][ncol] ]


pscoast plots grayshaded, colored, or textured land-masses [or water-masses] on maps and [optionally] draws coastlines, rivers, and political boundaries. Alternatively, it can (1) issue clip paths that will contain all land or all water areas, or (2) dump the data to an ASCII table. The datafiles come in 5 different resolutions: (f)ull, (h)igh, (i)ntermediate, (l)ow, and (c)rude. The full resolution files amount to more than 55 Mb of data and provide great detail; for maps of larger geographical extent it is more economical to use one of the other resolutions. If the user selects to paint the land-areas and does not specify fill of water-areas then the latter will be transparent (i.e., earlier graphics drawn in those areas will not be overwritten). Likewise, if the water-areas are painted and no land fill is set then the land-areas will be transparent. The PostScript code is written to standard output.

No space between the option flag and the associated arguments. Use upper case for the option flags and lower case for modifiers.


Selects the map projection. Scale is UNIT/degree, 1:xxxxx, or width in UNIT (upper case modifier). UNIT is cm, inch, or m, depending on the MEASURE_UNIT setting in .gmtdefaults4, but this can be overridden on the command line by appending c, i, or m to the scale/width value. For map height, max dimension, or min dimension, append h, +, or - to the width, respectively.

More details can be found in the psbasemap man pages.


−Jclon0/lat0/scale (Cassini)
lon0/scale (Miller)
scale (Mercator - Greenwich and Equator as origin)
lon0/lat0/scale (Mercator - Give meridian and standard parallel)
lon0/lat0/azimuth/scale (Oblique Mercator - point and azimuth)
lon0/lat0/lon1/lat1/scale (Oblique Mercator - two points)
lon0/lat0/lonp/latp/scale (Oblique Mercator - point and pole)
lon0/scale (Equidistant Cylindrical Projection (Plate Carree))
lon0/scale (TM - Transverse Mercator, with Equator as y = 0)
lon0/lat0/scale (TM - Transverse Mercator, set origin)
zone/scale (UTM - Universal Transverse Mercator)
lon0/lats/scale (Basic Cylindrical Projection)


−Jalon0/lat0/scale (Lambert)
lon0/lat0/scale (Equidistant)
lon0/lat0/horizon/scale (Gnomonic)
lon0/lat0/scale (Orthographic)
lon0/lat0/[slat/]scale (General Stereographic)


−Jblon0/lat0/lat1/lat2/scale (Albers)
lon0/lat0/lat1/lat2/scale (Equidistant)
lon0/lat0/lat1/lat2/scale (Lambert)


−Jhlon0/scale (Hammer)
lon0/scale (Sinusoidal)
[f|s]lon0/scale (Eckert IV (f) and VI (s))
lon0/scale (Robinson)
lon0/scale (Winkel Tripel)
lon0/scale (Van der Grinten)
lon0/scale (Mollweide)


−Jp[a]scale[/origin][r|z] (Polar coordinates (theta,r))
x-scale[d|l|ppow|t|T][/y-scale[d|l|ppow|t|T]] (Linear, log, and power scaling)


west, east, south, and north specify the Region of interest, and you may specify them in decimal degrees or in [+-]dd:mm[][W|E|S|N] format. Append r if lower left and upper right map coordinates are given instead of wesn. The two shorthands −Rg −Rd stand for global domain (0/360 or -180/+180 in longitude respectively, with -90/+90 in latitude).



Features with an area smaller than min_area in km^2 or of hierarchical level that is lower than min_level or higher than max_level will not be plotted [Default is 0/0/4 (all features)]. See DATABASE INFORMATION below for more details.


Sets map boundary annotation and tickmark intervals; see the psbasemap man page for all the details.


Set the shade (0−255), color (r/g/b), or pattern (p|Pdpi/pattern; see −G) for lakes [Default is the fill chosen for "wet" areas (−S)].


Selects the resolution of the data set to use ((f)ull, (h)igh, (i)ntermediate, (l)ow, and (c)rude). The resolution drops off by 80% between data sets. [Default is l].


Sets the viewpoint’s azimuth and elevation (for perspective view) [180/90].


Select painting or clipping of "dry" areas. Append a shade, color, pattern, or c for clipping. Specify the grey shade (0−255) or color (r/g/b, each in range 0−255; h-s-v, ranges 0−360, 0−1, 0−1; or c/m/y/k, each in range 0−100%; or valid color name). Alternatively, specify −Gpdpi/pattern, where pattern gives the number of the built-in pattern (1-90) or the name of a Sun 1-, 8-, or 24-bit raster file. The dpi sets the resolution of the image. For 1-bit rasters: use −GP for inverse video, or append :Fcolor[B[color]] to specify fore- and background colors (use color = - for transparency). See GMT Cookbook & Technical Reference Appendix E for information on individual patterns.


Draw rivers. Specify the type of rivers and [optionally] append pen attributes [Default pen: width = 1, color = black, texture = solid]. pen is a comma delimetered list of width, color and texture, each of which is optional. width can be indicated as a measure (points, centimeters, inches) or as faint, thin[ner|nest], thick[er|est], fat[ter|test], or obese. color specifies a grey shade (0−255) or color (r/g/b, each in range 0−255; h-s-v, ranges 0−360, 0−1, 0−1; or c/m/y/k, each in range 0−100%; or valid color name). texture is a combination of dashes ‘-’ and dots ‘.’.

Choose from the list of river types below. Repeat option −I as often as necessary.

1 = Permanent major rivers

2 = Additional major rivers

3 = Additional rivers

4 = Minor rivers

5 = Intermittent rivers - major

6 = Intermittent rivers - additional

7 = Intermittent rivers - minor

8 = Major canals

9 = Minor canals

10 = Irrigation canals

a = All rivers and canals (1-10)

r = All permanent rivers (1-4)

i = All intermittent rivers (5-7)

c = All canals (8-10)


Sets the vertical scaling (for 3-D maps). Same syntax as −Jx.


More PostScript code will be appended later [Default terminates the plot system].


Draws a simple map scale centered on lon0/lat0. Use −Lx to specify x/y position instead. Scale is calculated at latitude slat (optionally supply longitude slon for oblique projections [Default is central meridian]), length is in km [miles if m is appended; nautical miles if n is appended]. Use −Lf to get a "fancy" scale [Default is plain]. The default label equals the distance unit (km, miles, nautical miles) and is justified on top of the scale [t]. Change this by giving your own label (or - to keep the default) and justification (l(eft), r(ight), t(op), b(ottom), and u(unit) - using the label as a unit appended to all distance annotations along the scale). If you want to place a rectangle behind the scale, specify pen and/or fill parameters with the +p and +f modifiers.


Dumps a single multisegment ASCII (or binary, see −bo) file to standard output. No plotting occurs. Specify any combination of −W, −I, −N. Optionally, you may append the flag character that is written at the start of each segment header [’>’].


Draw political boundaries. Specify the type of boundary and [optionally] append pen attributes [Default pen: width = 1, color = black, texture = solid]. pen is a comma delimetered list of width, color and texture, each of which is optional. width can be indicated as a measure (points, centimeters, inches) or as faint, thin[ner|nest], thick[er|est], fat[ter|test], or obese. color specifies a grey shade (0−255) or color (r/g/b, each in range 0−255; h-s-v, ranges 0−360, 0−1, 0−1; or c/m/y/k, each in range 0−100%; or valid color name). texture is a combination of dashes ‘-’ and dots ‘.’.

Choose from the list of boundaries below. Repeat option −N as often as necessary.

1 = National boundaries

2 = State boundaries within the Americas

3 = Marine boundaries

a = All boundaries (1-3)


Selects Overlay plot mode [Default initializes a new plot system].


Selects Portrait plotting mode [GMT Default is Landscape, see gmtdefaults to change this].


Mark end of existing clip path. No projection information is needed.


Select painting or clipping of "wet" areas. Append the shade (0−255), color (r/g/b), pattern (see −G), or c for clipping.


Draws a simple map directional rose centered on lon0/lat0. Use −Tx to specify x/y position instead. The size is the diameter of the rose, and optional label information can be specified to override the default values of W, E, S, and N (Give :: to suppress all labels). The default [plain] map rose only labels north. Use −Tf to get a "fancy" rose, and specify what kind of rose you want drawn. The default [1] draws the two principal E-W, N-S orientations, 2 adds the two intermediate NW-SE and NE-SW orientations, while 3 adds the eight minor orientations WNW-ESE, NNW-SSE, NNE-SSW, and ENE-WSW. For a magnetic compass rose, specify −Tm. If given, info must be the two parameters dec/dlabel, where dec is the magnetic declination and dlabel is a label for the magnetic compass needle (specify ’-’ to format a label from dec). Then, both directions to geographic and magnetic north are plotted [Default is geographic only]. If the north label = * then a north star is plotted instead of the north label. Annotation and two levels of tick intervals for geographic and magnetic directions are 10/5/1 and 30/5/1 degrees, respectively; override these settings by appending +gints[/mints]. Color and pen attributes are taken from COLOR_BACKGROUND and TICK_PEN, respectively, while label fonts and sizes follow the usual annotation, label, and header font settings.


Draw Unix System time stamp on plot. User may specify where the lower left corner of the stamp should fall on the page relative to lower left corner of plot. Optionally, append a label, or c (which will plot the command string.). The GMT parameters UNIX_TIME and UNIX_TIME_POS can affect the appearance; see the gmtdefaults man page for details.


Selects verbose mode, which will send progress reports to stderr [Default runs "silently"].


Draw coastlines. [Default is no coastlines]. Append pen attributes [Defaults: width = 1, color = black, texture = solid].

−X −Y

Shift origin of plot by (x-shift,y-shift), and opetionally append units (c, i, m, p). Prepend a for absolute coordinates; the default (r) will reset plot origin. Give c to center plot using current page size.


For 3-D projections: Sets the z-level of the coastlines [0].


Specifies the number of plot copies. [Default is 1].


Selects binary output. Append s for single precision [Default is d (double)]. Uppercase S (or D) will force byte-swapping. Optionally, append ncol, the number of desired columns in your binary output file. Optionally, append ncol, the number of columns in your binary file if it exceeds the columns needed by the program.


To plot a green Africa with white outline on blue background, with permanent major rivers in thick blue pen, additional major rivers in thin blue pen, and national borders as dashed lines on a Mercator map at scale 0.1 inch/degree, use

pscoast −R-30/30/-40/40 −Jm0.1i −B5 −I1/1p/0/0/255 −I2/0.25p/0/0/255 −N1/0.25tap −W0.25p/255/255/255 −G0/255/0 −S0/0/255 −P >

To plot Iceland using the lava pattern (# 28) at 100 dots per inch, on a Mercator map at scale 1 cm/degree, run

pscoast −R-30/-10/60/65 −Jm1c −B5 −Gp100/28 >

To initiate a clip path for Africa so that the subsequent colorimage of gridded topography is only seen over land, using a Mercator map at scale 0.1 inch/degree, use

pscoast −R-30/30/-40/40 −Jm0.1i −B5 −Gc −P −K >
grdimage −Jm
0.1i etopo5.grd −Ccolors.cpt −O −K >>
pscoast −Q −O


The coastline database is GSHHS which is compiled from two sources: World Vector Shorelines (WVS) and CIA World Data Bank II (WDBII). In particular, all level-1 polygons (ocean-land boundary) are derived from the more accurate WVS while all higher level polygons (level 2-4, representing land/lake, lake/island-in-lake, and island-in-lake/lake-in-island-in-lake boundaries) are taken from WDBII. Much processing has taken place to convert WVS and WDBII data into usable form for GMT: assembling closed polygons from line segments, checking for duplicates, and correcting for crossings between polygons. The area of each polygon has been determined so that the user may choose not to draw features smaller than a minimum area (see −A); one may also limit the highest hierarchical level of polygons to be included (4 is the maximum). The 4 lower-resolution databases were derived from the full resolution database using the Douglas-Peucker line-simplification algorithm. The classification of rivers and borders follow that of the WDBII. See the GMT Cookbook and Technical Reference Appendix K for further details.

pscoast will first look for coastline files in directory $GMTHOME/share (where $GMTHOME is an environmental variable). If the desired file is not found, it will look for the file coastline.conf in the same directory. This file may contain any number of records that each holds the full pathname of an alternative directory. Comment lines (#) and blank lines are allowed. The desired file is then sought for in the alternate directories.


The options to fill (−C −G −S) may not always work if the Azimuthal equidistant projection is chosen (−Je|E). If the antipole of the projection is in the oceans it will most likely work. If not, try to avoid using projection center coordinates that are even multiples of the coastline bin size (1, 2, 5, 10, and 20 degrees for f, h, i, l, c, respectively). This projection is not supported for clipping.
The political borders are for the most part 1970ies-style and do not reflect the recent border rearrangements in Europe. We intend to update these as high-resolution data become available to us.
Some users of pscoast will not be satisfied with what they find for the Antarctic shoreline. In Antarctica, the boundary between ice and ocean varies seasonally and inter-annually. There are some areas of permanent sea ice. In addition to these time-varying ice-ocean boundaries, there are also ice grounding lines where ice goes from floating on the sea to sitting on land, and lines delimiting areas of rock outcrop. For consistency’s sake, we have used the World Vector Shoreline throughout the world in pscoast, as described in the GMT Cookbook Appendix K. Users who need specific boundaries in Antarctica should get the Antarctic Digital Database, prepared by the British Antarctic Survey, Scott Polar Research Institute, World Conservation Monitoring Centre, under the auspices of the Scientific Committee on Antarctic Research. This data base contains various kinds of limiting lines for Antarctica and is available on CD-ROM. It is published by the Scientific Committee on Antarctic Research, Scott Polar Research Institute, Lensfield Road, Cambridge CB2 1ER, United Kingdom.


gmtdefaults(l), GMT(l), grdlandmask(l), psbasemap(l)