psbasemap(1) GMT psbasemap(1)
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 a|)
Select map projection.
-Rxmin/xmax/ymin/ymax[+r][+uunit] (more a|)
Specify the region of interest.
For perspective view p, optionally append /zmin/zmax. (more a|)
OPTIONAL ARGUMENTS
-A[file]
No plotting is performed. Instead, we determine the geographi-
cal 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 coordi-
nates are written to file or to standard output if no file is
specified.
-B[p|s]parameters (more a|)
Set map boundary frame and axes attributes.
-D[unit]xmin/xmax/ymin/ymax[r][+sfile][+t] | -D[g|j|J|n|x]ref-
point+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) coordi-
nates, 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 justifica-
tion code justify (see pstext). Note: If -Dj is used then jus-
tify defaults to the same as refpoint, if -DJ is used then jus-
tify 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. Alter-
natively, 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][+cclear-
ances][+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 clear-
ance 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 val-
ues 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 rela-
tive 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 a|)
Set z-axis scaling; same syntax as -Jx.
-K (more a|)
Do not finalize the PostScript plot.
-L[g|j|J|n|x]ref-
point+c[slon/]slat+wlength[e|f|k|M|n|u][+aalign][+f][+jjus-
tify][+l[label]][+odx[/dy]][+u]
Draws a simple map scale centered on the reference point speci-
fied 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 afancya 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 a|)
Append to existing PostScript plot.
-P (more a|)
Select aPortraita plot orientation.
-Td[g|j|J|n|x]refpoint+wwidth[+f[level]][+jjus-
tify][+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 sys-
tems: (1) Use g for map (user) coordinates, (2) use j for set-
ting 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 justi-
fication 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 afancya 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-sepa-
rated 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][+jjus-
tify][+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 jus-
tification 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 refer-
ence 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 a|)
Draw GMT time stamp logo on plot.
-V[level] (more a|)
Select verbosity level [c].
-X[a|c|f|r][x-shift[u]]
-Y[a|c|f|r][y-shift[u]] (more a|)
Shift plot origin.
-f[i|o]colinfo (more a|)
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 a|)
Select perspective view.
-t[transp] (more a|)
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 explana-
tion 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 = aDistancea and ylabel = aNo of
samplesa, 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 anno-
tated 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 inter-
vals 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 sub-
stitute -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 alti-
tude 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 aSalinity measurementsa, 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 arbi-
trary 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 alook righta. 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 infor-
mation 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 warn-
ing will notify the user if -V is set.
BUGS
The -B option is somewhat complicated to explain and comprehend. How-
ever, it is fairly simple for most applications (see examples).
SEE ALSO
gmt(1), gmt.conf(5), gmtcolors(5)
COPYRIGHT
2017, P. Wessel, W. H. F. Smith, R. Scharroo, J. Luis, and F. Wobbe
5.4.2 Jun 24, 2017 psbasemap(1)
gmt5 5.4.2 - Generated Thu Jun 29 15:02:16 CDT 2017