Provided by: gmt-common_5.4.3+dfsg-1_all 
NAME
psbasemap - Plot PostScript base maps
SYNOPSIS
psbasemap -Jparameters
-Rwest/east/south/north[/zmin/zmax][+r] [ -B[p|s]parameters ] [ -A[file] ] [ -Dinsert box ] [ -Fbox
] [ -K ] [ -Jz|Zparameters ] [ -Lscalebar ] [ -O ] [ -P ] [ -U[stamp] ] [ -Trose ] [ -Tmag_rose ]
[ -V[level] ] [ -Xx_offset ] [ -Yy_offset ] [ -fflags ] [ -pflags ] [ -ttransp ]
Note: No space is allowed between the option flag and the associated arguments.
DESCRIPTION
psbasemap creates PostScript code that will produce a basemap. Several map projections are available,
and the user may specify separate tick-mark intervals for boundary annotation, ticking, and [optionally]
gridlines. A simple map scale or directional rose may also be plotted. At least one of the options -B,
-L, or -T must be specified.
REQUIRED ARGUMENTS
-Jparameters (more …)
Select map projection.
-Rxmin/xmax/ymin/ymax[+r][+uunit] (more …)
Specify the region of interest.
For perspective view p, optionally append /zmin/zmax. (more …)
OPTIONAL ARGUMENTS
-A[file]
No plotting is performed. Instead, we determine the geographical coordinates of the polygon
outline for the (possibly oblique) rectangular map domain. The plot domain must be given via -R
and -J, with no other options allowed. The sampling interval is controlled via MAP_LINE_STEP
parameter. The coordinates are written to file or to standard output if no file is specified.
-B[p|s]parameters (more …)
Set map boundary frame and axes attributes.
-D[unit]xmin/xmax/ymin/ymax[r][+sfile][+t] |
-D[g|j|J|n|x]refpoint+wwidth[/height][+jjustify][+odx[/dy]][+sfile][+t]
Draw a simple map insert box on the map. Requires -F. Specify the box in one of three ways: (a)
Give west/east/south/north of geographic rectangle bounded by parallels and meridians; append r if
the coordinates instead are the lower left and upper right corners of the desired rectangle. (b)
Give uxmin/xmax/ymin/ymax of bounding rectangle in projected coordinates (here, u is the
coordinate unit). (c) Give the reference point on the map for the insert using one of four
coordinate systems: (1) Use -Dg for map (user) coordinates, (2) use -Dj or -DJ for setting
refpoint via a 2-char justification code that refers to the (invisible) map domain rectangle, (3)
use -Dn for normalized (0-1) coordinates, or (4) use -Dx for plot coordinates (inches, cm, etc.).
Append +wwidth[/height] of bounding rectangle or box in plot coordinates (inches, cm, etc.). By
default, the anchor point on the scale is assumed to be the bottom left corner (BL), but this can
be changed by appending +j followed by a 2-char justification code justify (see pstext). Note: If
-Dj is used then justify defaults to the same as refpoint, if -DJ is used then justify defaults to
the mirror opposite of refpoint. Add +o to offset the inset fig by dx/dy away from the refpoint
point in the direction implied by justify (or the direction implied by -Dj or -DJ). If you need
access to the placement of the lower left corner of the map insert and its dimensions in the
current map unit, use +sfile to write this information to file. Alternatively, you may append +t
to translate the plot origin to the lower left corner of the map insert. Specify insert box
attributes via the -F option [outline only].
-F[d|l|t][+cclearances][+gfill][+i[[gap/]pen]][+p[pen]][+r[radius]][+s[[dx/dy/][shade]]]
Without further options, draws a rectangular border around any map insert (-D), map scale (-L) or
map rose (-T) using MAP_FRAME_PEN; specify a different pen with +ppen. Add +gfill to fill the
logo box [no fill]. Append +cclearance where clearance is either gap, xgap/ygap, or
lgap/rgap/bgap/tgap where these items are uniform, separate in x- and y-direction, or individual
side spacings between logo and border. Append +i to draw a secondary, inner border as well. We
use a uniform gap between borders of 2p and the MAP_DEFAULT_PEN unless other values are specified.
Append +r to draw rounded rectangular borders instead, with a 6p corner radius. You can override
this radius by appending another value. Finally, append +s to draw an offset background shaded
region. Here, dx/dy indicates the shift relative to the foreground frame [4p/-4p] and shade sets
the fill style to use for shading [gray50]. Used in combination with -D, -L or -T. To specify
separate parameters for the various map features, append d|l|t to -F to specify panel parameters
for just that panel [Default uses the same panel parameters for all selected map features].
-Jz|Zparameters (more …)
Set z-axis scaling; same syntax as -Jx.
-K (more …)
Do not finalize the PostScript plot.
-L[g|j|J|n|x]refpoint+c[slon/]slat+wlength[e|f|k|M|n|u][+aalign][+f][+jjustify][+l[label]][+odx[/dy]][+u]
Draws a simple map scale centered on the reference point specified using one of four coordinate
systems: (1) Use -Lg for map (user) coordinates, (2) use -Lj or -LJ for setting refpoint via a
2-char justification code that refers to the (invisible) map domain rectangle, (3) use -Ln for
normalized (0-1) coordinates, or (4) use -Lx for plot coordinates (inches, cm, etc.). Scale is
calculated for latitude slat (optionally supply longitude slon for oblique projections [Default is
central meridian]), length is in km, or append unit from e|f|k|M|n|u. Change the label alignment
with +aalign (choose among l(eft), r(ight), t(op), and b(ottom)). Append +f to get a “fancy”
scale [Default is plain]. By default, the anchor point on the map scale is assumed to be the
center of the scale (MC), but this can be changed by appending +j followed by a 2-char
justification code justify (see pstext for list and explanation of codes). Append +l to select
the default label, which equals the distance unit (meter, foot, km, mile, nautical mile, US survey
foot) and is justified on top of the scale [t]. Change this by giving your own label (append
+llabel). Add +o to offset the map scale by dx/dy away from the refpoint in the direction implied
by justify (or the direction implied by -Dj or -DJ). Select +u to append the unit to all distance
annotations along the scale (for the plain scale, +u will instead select the unit to be appended
to the distance length). Note: Use FONT_LABEL to change the label font and FONT_ANNOT_PRIMARY to
change the annotation font. The height of the map scale is controlled by MAP_SCALE_HEIGHT, and
the pen thickness is set by MAP_TICK_PEN_PRIMARY. See -F on how to place a panel behind the
scale.
-O (more …)
Append to existing PostScript plot.
-P (more …)
Select “Portrait” plot orientation.
-Td[g|j|J|n|x]refpoint+wwidth[+f[level]][+jjustify][+lw,e,s,n][+odx[/dy]]
-Td draws a map directional rose on the map at the location defined by the reference and anchor
points: Give the reference point on the map for the rose using one of four coordinate systems: (1)
Use g for map (user) coordinates, (2) use j for setting refpoint via a 2-char justification code
that refers to the (invisible) map domain rectangle, (3) use n for normalized (0-1) coordinates,
or (4) use x for plot coordinates (inches, cm, etc.) [Default]. You can offset the reference
point by dx/dy in the direction implied by justify. By default, the anchor point on the scale is
assumed to be the center of the rose (MC), but this can be changed by appending +j followed by a
2-char justification code justify (see pstext for list and explanation of codes). Note: If -Dj is
used then justify defaults to the same as refpoint, if -DJ is used then justify defaults to the
mirror opposite of refpoint. Add +o to offset the color scale by dx/dy away from the refpoint in
the direction implied by justify (or the direction implied by -Dj or -DJ). Append +wwidth to set
the width of the rose in plot coordinates (in inches, cm, or points). Add +f to get a “fancy”
rose, and specify in level what 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. Label the cardinal points W,E,S,N by
adding +l and append your own four comma-separated strings to override the default. Skip a
specific label by leaving it blank. See Placing-dir-map-roses and -F on how to place a panel
behind the scale.
-Tm[g|j|J|n|x]refpoint+wwidth[+ddec[/dlabel]]][+ipen][+jjustify][+lw,e,s,n][+ppen][+tints][+odx[/dy]]
-Tm draws a map magnetic rose on the map at the location defined by the reference and anchor points:
Give the reference point on the map for the rose using one of four coordinate systems: (1) Use g for
map (user) coordinates, (2) use j for setting refpoint via a 2-char justification code that refers to
the (invisible) map domain rectangle, (3) use n for normalized (0-1) coordinates, or (4) use x for
plot coordinates (inches, cm, etc.) [Default]. You can offset the reference point by dx/dy in the
direction implied by justify. By default, the anchor point on the scale is assumed to be the center
of the rose (MC), but this can be changed by appending +j followed by a 2-char justification code
justify (see pstext for list and explanation of codes). Note: If -Dj is used then justify defaults to
the same as refpoint, if -DJ is used then justify defaults to the mirror opposite of refpoint. Add +o
to offset the color scale by dx/dy away from the refpoint in the direction implied by justify (or the
direction implied by -Dj or -DJ). Append +wwidth to set the width of the rose in plot coordinates (in
inches, cm, or points). Use +d to assign the magnetic declination and set dlabel, which is a label
for the magnetic compass needle (Leave empty to format a label from dec, or give - to bypass
labeling). With +d, both directions to geographic and magnetic north are plotted [Default is
geographic only]. If the north label is * then a north star is plotted instead of the north label.
Annotation and two levels of tick intervals for both geographic and magnetic directions default to
30/5/1 degrees; override these settings by appending +tints, and append six slash-separated intervals
to set both the geographic (first three) and magnetic (last three) intervals. Label the cardinal
points W,E,S,N by adding +l and append your own four comma-separated strings to override the default.
Skip a specific label by leaving it blank. Number GMT default parameters control pens, fonts, and
color. See Placing-dir-map-roses and -F on how to place a panel behind the scale.
-U[[just]/dx/dy/][c|label] (more …)
Draw GMT time stamp logo on plot.
-V[level] (more …)
Select verbosity level [c].
-X[a|c|f|r][x-shift[u]]
-Y[a|c|f|r][y-shift[u]] (more …)
Shift plot origin.
-f[i|o]colinfo (more …)
Specify data types of input and/or output columns. This applies only to the coordinates specified
in the -R option.
-p[x|y|z]azim[/elev[/zlevel]][+wlon0/lat0[/z0]][+vx0/y0] (more …)
Select perspective view.
-t[transp] (more …)
Set PDF transparency level in percent.
-^ or just -
Print a short message about the syntax of the command, then exits (NOTE: on Windows just use -).
-+ or just +
Print an extensive usage (help) message, including the explanation of any module-specific option
(but not the GMT common options), then exits.
-? or no arguments
Print a complete usage (help) message, including the explanation of all options, then exits.
EXAMPLES
The following section illustrates the use of the options by giving some examples for the available map
projections. Note how scales may be given in several different ways depending on the projection. Also
note the use of upper case letters to specify map width instead of map scale.
NON-GEOGRAPHICAL PROJECTIONS
Linear x-y plot
To make a linear x/y frame with all axes, but with only left and bottom axes annotated, using xscale =
yscale = 1.0, ticking every 1 unit and annotating every 2, and using xlabel = “Distance” and ylabel = “No
of samples”, use
gmt psbasemap -R0/9/0/5 -Jx1 -Bf1a2 -Bx+lDistance -By+l"No of samples" -BWeSn > linear.ps
Log-log plot
To make a log-log frame with only the left and bottom axes, where the x-axis is 25 cm and annotated every
1-2-5 and the y-axis is 15 cm and annotated every power of 10 but has tick-marks every 0.1, run
gmt psbasemap -R1/10000/1e20/1e25 -JX25cl/15cl -Bx2+lWavelength -Bya1pf3+lPower -BWS > loglog.ps
Power axes
To design an axis system to be used for a depth-sqrt(age) plot with depth positive down, ticked and
annotated every 500m, and ages annotated at 1 my, 4 my, 9 my etc, use
gmt psbasemap -R0/100/0/5000 -Jx1p0.5/-0.001 -Bx1p+l"Crustal age" -By500+lDepth > power.ps
Polar (theta,r) plot
For a base map for use with polar coordinates, where the radius from 0 to 1000 should correspond to 3
inch and with gridlines and ticks intervals automatically determined, use
gmt psbasemap -R0/360/0/1000 -JP6i -Bafg > polar.ps
CYLINDRICAL MAP PROJECTIONS
Cassini
A 10-cm-wide basemap using the Cassini projection may be obtained by
gmt psbasemap -R20/50/20/35 -JC35/28/10c -P -Bafg -B+tCassini > cassini.ps
Mercator [conformal]
A Mercator map with scale 0.025 inch/degree along equator, and showing the length of 5000 km along the
equator (centered on 1/1 inch), may be plotted as
gmt psbasemap -R90/180/-50/50 -Jm0.025i -Bafg -B+tMercator -Lx1i/1i+c0+w5000k > mercator.ps
Miller
A global Miller cylindrical map with scale 1:200,000,000 may be plotted as
gmt psbasemap -Rg -Jj180/1:200000000 -Bafg -B+tMiller > miller.ps
Oblique Mercator [conformal]
To create a page-size global oblique Mercator basemap for a pole at (90,30) with gridlines every 30
degrees, run
gmt psbasemap -R0/360/-70/70 -Joc0/0/90/30/0.064cd -B30g30 -B+t"Oblique Mercator" > oblmerc.ps
Transverse Mercator [conformal]
A regular Transverse Mercator basemap for some region may look like
gmt psbasemap -R69:30/71:45/-17/-15:15 -Jt70/1:1000000 -Bafg -B+t"Survey area" -P > transmerc.ps
Equidistant Cylindrical Projection
This projection only needs the central meridian and scale. A 25 cm wide global basemap centered on the
130E meridian is made by
gmt psbasemap -R-50/310/-90/90 -JQ130/25c -Bafg -B+t"Equidistant Cylindrical" > cyl_eqdist.ps
Universal Transverse Mercator [conformal]
To use this projection you must know the UTM zone number, which defines the central meridian. A UTM
basemap for Indo-China can be plotted as
gmt psbasemap -R95/5/108/20r -Ju46/1:10000000 -Bafg -B+tUTM > utm.ps
Cylindrical Equal-Area
First select which of the cylindrical equal-area projections you want by deciding on the standard
parallel. Here we will use 45 degrees which gives the Gall-Peters projection. A 9 inch wide global
basemap centered on the Pacific is made by
gmt psbasemap -Rg -JY180/45/9i -Bafg -B+tGall-Peters > gall-peters.ps
CONIC MAP PROJECTIONS
Albers [equal-area]
A basemap for middle Europe may be created by
gmt psbasemap -R0/90/25/55 -Jb45/20/32/45/0.25c -Bafg -B+t"Albers Equal-area" > albers.ps
Lambert [conformal]
Another basemap for middle Europe may be created by
gmt psbasemap -R0/90/25/55 -Jl45/20/32/45/0.1i -Bafg -B+t"Lambert Conformal Conic" > lambertc.ps
Equidistant
Yet another basemap of width 6 inch for middle Europe may be created by
gmt psbasemap -R0/90/25/55 -JD45/20/32/45/6i -Bafg -B+t"Equidistant conic" > econic.ps
Polyconic
A basemap for north America may be created by
gmt psbasemap -R-180/-20/0/90 -JPoly/4i -Bafg -B+tPolyconic > polyconic.ps
AZIMUTHAL MAP PROJECTIONS
Lambert [equal-area]
A 15-cm-wide global view of the world from the vantage point -80/-30 will give the following basemap:
gmt psbasemap -Rg -JA-80/-30/15c -Bafg -B+t"Lambert Azimuthal" > lamberta.ps
Follow the instructions for stereographic projection if you want to impose rectangular boundaries on the
azimuthal equal-area map but substitute -Ja for -Js.
Equidistant
A 15-cm-wide global map in which distances from the center (here 125/10) to any point is true can be
obtained by:
gmt psbasemap -Rg -JE125/10/15c -Bafg -B+tEquidistant > equi.ps
Gnomonic
A view of the world from the vantage point -100/40 out to a horizon of 60 degrees from the center can be
made using the Gnomonic projection:
gmt psbasemap -Rg -JF-100/40/60/6i -Bafg -B+tGnomonic > gnomonic.ps
Orthographic
A global perspective (from infinite distance) view of the world from the vantage point 125/10 will give
the following 6-inch-wide basemap:
gmt psbasemap -Rg -JG125/10/6i -Bafg -B+tOrthographic > ortho.ps
General Perspective
The -JG option can be used in a more generalized form, specifying altitude above the surface, width and
height of the view point, and twist and tilt. A view from 160 km above -74/41.5 with a tilt of 55 and
azimuth of 210 degrees, and limiting the viewpoint to 30 degrees width and height will product a
6-inch-wide basemap:
gmt psbasemap -Rg -JG-74/41.5/160/210/55/30/30/6i -Bafg -B+t"General Perspective" > genper.ps
Stereographic [conformal]
To make a polar stereographic projection basemap with radius = 12 cm to -60 degree latitude, with plot
title “Salinity measurements”, using 5 degrees annotation/tick interval and 1 degree gridlines, run
gmt psbasemap -R-45/45/-90/-60 -Js0/-90/12c/-60 -B5g1 -B+t"Salinity measurements" > stereo1.ps
To make a 12-cm-wide stereographic basemap for Australia from an arbitrary view point (not the poles),
and use a rectangular boundary, we must give the pole for the new projection and use the -R option to
indicate the lower left and upper right corners (in lon/lat) that will define our rectangle. We choose a
pole at 130/-30 and use 100/-45 and 160/-5 as our corners. The command becomes
gmt psbasemap -R100/-45/160/-5r -JS130/-30/12c -Bafg -B+t"General Stereographic View" > stereo2.ps
MISCELLANEOUS MAP PROJECTIONS
Hammer [equal-area]
The Hammer projection is mostly used for global maps and thus the spherical form is used. To get a world
map centered on Greenwich at a scale of 1:200000000, use
gmt psbasemap -Rd -Jh0/1:200000000 -Bafg -B+tHammer > hammer.ps
Sinusoidal [equal-area]
To make a sinusoidal world map centered on Greenwich, with a scale along the equator of 0.02 inch/degree,
use
gmt psbasemap -Rd -Ji0/0.02i -Bafg -B+tSinusoidal > sinus1.ps
To make an interrupted sinusoidal world map with breaks at 160W, 20W, and 60E, with a scale along the
equator of 0.02 inch/degree, run the following sequence of commands:
gmt psbasemap -R-160/-20/-90/90 -Ji-90/0.02i -Bx30g30 -By15g15 -BWesn -K > sinus_i.ps
gmt psbasemap -R-20/60/-90/90 -Ji20/0.02i -Bx30g30 -By15g15 -Bwesn -O -K -X2.8i >> sinus_i.ps
gmt psbasemap -R60/200/-90/90 -Ji130/0.02i -Bx30g30 -By15g15 -BwEsn -O -X1.6i >> sinus_i.ps
Eckert IV [equal-area]
Pseudo-cylindrical projection typically used for global maps only. Set the central longitude and scale,
e.g.,
gmt psbasemap -Rg -Jkf180/0.064c -Bafg -B+t"Eckert IV" > eckert4.ps
Eckert VI [equal-area]
Another pseudo-cylindrical projection typically used for global maps only. Set the central longitude and
scale, e.g.,
gmt psbasemap -Rg -Jks180/0.064c -Bafg -B+t"Eckert VI" > eckert6.ps
Robinson
Projection designed to make global maps “look right”. Set the central longitude and width, e.g.,
gmt psbasemap -Rd -JN0/8i -Bafg -B+tRobinson > robinson.ps
Winkel Tripel
Yet another projection typically used for global maps only. You can set the central longitude, e.g.,
gmt psbasemap -R90/450/-90/90 -JR270/25c -Bafg -B+t"Winkel Tripel" > winkel.ps
Mollweide [equal-area]
The Mollweide projection is also mostly used for global maps and thus the spherical form is used. To get
a 25-cm-wide world map centered on the Dateline:
psbasemap -Rg -JW180/25c -Bafg -B+tMollweide > mollweide.ps
Van der Grinten
The Van der Grinten projection is also mostly used for global maps and thus the spherical form is used.
To get a 18-cm-wide world map centered on the Dateline:
gmt psbasemap -Rg -JV180/18c -Bafg -B+t"Van der Grinten" > grinten.ps
Arbitrary rotation
If you need to plot a map but have it rotated about a vertical axis then use the -p option. For
instance, the rotate the basemap below 90 degrees about an axis centered on the map, try
gmt psbasemap -R10/40/10/40 -JM10c -P -Bafg -B+t"I am rotated" -p90+w25/25 -Xc > rotated.ps
CUSTOM LABELS OR INTERVALS
The -B option sets up a regular annotation interval and the annotations derive from the corresponding x,
y, or z coordinates. However, some applications requires special control on which annotations to plot
and even replace the annotation with other labels. This is achieved by using cintfile in the -B option,
where intfile contains all the information about annotations, ticks, and even gridlines. Each record is
of the form coord type [label], where coord is the coordinate for this annotation (or tick or gridline),
type is one or more letters from a (annotation), i interval annotation, f tickmark, and g gridline. Note
that a and i are mutually exclusive and cannot both appear in the same intfile. Both a and i requires you
to supply a label which is used as the plot annotation. If not given then a regular formatted annotation
based on the coordinate will occur.
RESTRICTIONS
For some projections, a spherical earth is implicitly assumed. A warning will notify the user if -V is
set.
BUGS
The -B option is somewhat complicated to explain and comprehend. However, it is fairly simple for most
applications (see examples).
SEE ALSO
gmt, gmt.conf, gmtcolors
COPYRIGHT
2018, P. Wessel, W. H. F. Smith, R. Scharroo, J. Luis, and F. Wobbe
5.4.3 Jan 03, 2018 PSBASEMAP(1gmt)