NAME

      psbasemap - To plot PostScript basemaps

SYNOPSIS

      psbasemap -Btickinfo -Jparameters -Rwest/east/south/north[r] [
      -Eazimuth/elevation ] [ -Gfill ] [ -K ] [
      -L[f][x]lon0/lat0/slat/length[m|n] ] [ -O ] [ -P ] [ -U[/dx/dy/][label]
      ] [ -V ] [ -Xx-shift ] [ -Yy-shift ] [ -Xy-level ] [ -Zzlevel ] [
      -ccopies ]

DESCRIPTION

      psbasemap creates PostScript code that will produce a basemap.
      Several map projections are available, and the user may specify
      separate tickmark intervals for boundary annotation, ticking, and
      [optionally] gridlines.  A simple map scale may also be plotted.
           No space between the option flag and the associated arguments.
      Use upper case for the option flags and lower case for modifiers.

      -B   Sets map boundary tickmark intervals. tickinfo is a textstring
           made up of one or more concatenated substrings of the form
           [which]tick[m|c].  The optional which can be either a for
           annotation interval [Default], f for frame tick interval, or g
           for gridline interval.  If frame interval is not set, it is
           assumed to be the same as annotation interval. tick is the
           desired tick interval.  The optional m|c indicates minutes (m) or
           seconds (c).  To specify separate x and y ticks, separate the
           substrings that apply to the x and y axes with a slash [/] (If a
           3-D basemap is selected with -E, -Jz, a third substring
           pertaining to the vertical axis may be appended.)  For
           linear/log/power projections (-Jx): Labels for each axis can be
           added by surrounding them with colons.  If the first character in
           the label is a period, then the label is used as plot title.  If
           the label consists of more than one word, enclose the entire
           label in double quotes (e.g., :"my label":).
           By default, all 4 boundaries are plotted (referred to as W, E, S,
           N).  To change the default, append the code for those you want
           (e.g., WS for standard lower-left x- and y-axis system).  Upper
           case (e.g., W) means draw axis/tickmarks AND annotate it, whereas
           lower case (e.g., w) will only draw axis/tickmarks.  (If a 3-D
           basemap is selected with -E and -Jz, append Z or z to control the
           appearance of the vertical axis.  Append '+' to draw the outline
           of the cube defined by -R)
           For non-geographical projections: Give negative scale (in -Jx) or
           axis length (in -JX) to change the direction of increasing
           coordinates (i.e., to make the y-axis positive down).  For log10
           axes:  Annotations can be specified in one of three ways:  (1)
           tick can be 1, 2, or 3.  Annotations will then occur at 1, 1-2-5,
           or 1-2-3-4-...-9, respectively.  This option can also be used for
           the frame and grid intervals.  (2) An l is appended to the
           tickinfo string.  Then, log10 of the tick value is plotted at
           every integer log10 value.  (3) A p is appended to the tickinfo
           string.  Then, annotations appear as 10 raised to log10 of the
           tick value.  For power axes: Annotations can be specified in one
           of two ways:  (1) tick sets the regular annotation interval.  (2)
           A p is appended to the tickinfo string.  Then, the annotation
           interval is expected to be in transformed units, but the
           annotation value will be plotted as untransformed units.  E.g.,
           if tick = 1 and power = 0.5 (i.e., sqrt), then equidistant
           annotations labeled 1-4-9... will appear.

      -J   Selects the map projection.  The following character determines
           the projection.  If the character is upper case then the
           argument(s) supplied as scale(s) is interpreted to be the map
           width (or axis lengths) in inch, else the scale argument(s) is
           the map scale (see its definition for each projection).  Choose
           one of the following projections (The E or C after projection
           names stands for Equal-Area and Conformal, respectively):

           CYLINDRICAL PROJECTIONS:

           -Jclon0/lat0/scale or -JClon0/lat0/width (Cassini)
                Give projection center and scale (1:xxxx or inch/degree).
           -Jjlon0/scale or -JJlon0/width (Miller Cylindrical Projection)
                Give the central meridian and scale (1:xxxx or inch/degree).
           -Jmparameters (Mercator [C]).  Specify one of:
                -Jmscale or -JMwidth
                     Give scale along equator (1:xxxx or inch/degree).
                -Jmlon0/lat0/scale or -JMlon0/lat0/width
                     Give central meridian, standard latitude and scale
           along parallel (1:xxxx or inch/degree).
           -Joparameters (Oblique Mercator [C]).  Specify one of:
                -Joalon0/lat0/azimuth/scale or -JOalon0/lat0/azimuth/width
                     Set projection center, azimuth of oblique equator, and
           scale.
                -Joblon0/lat0/lon1/lat1/scale or
           -JOblon0/lat0/lon1/lat1/scale
                     Set projection center, another point on the oblique
           equator, and scale.
                -Joclon0/lat0/lonp/latp/scale or
           -JOclon0/lat0/lonp/latp/scale
                     Set projection center, pole of oblique projection, and
           scale.
                Give scale along oblique equator (1:xxxx or inch/degree).
           -Jqlon0/scale or -JQlon0/width (Equidistant Cylindrical
           Projection (Plate Carree))
                Give the central meridian and scale (1:xxxx or inch/degree).
           -Jtlon0/scale or -JTlon0/width (TM - Transverse Mercator [C])
                Give the central meridian and scale (1:xxxx or inch/degree).
           -Juzone/scale or -JUzone/width (UTM - Universal Transverse
           Mercator [C])
                Give the zone number and scale (1:xxxx or inch/degree).
                Use negative zone numbers for the southern hemisphere.

           -Jylon0/lats/scale or -JYlon0/lats/width (Basic Cylindrical
           Projections [E])
                Give the central meridian, standard parallel, and scale
           (1:xxxx or inch/degree).
                The standard parallel is typically one of these (but can be
           any value):
                45   - The Peters projection
                37.4 - The Trystan Edwards projection
                30   - The Behrman projection
                0    - The Lambert projection

           AZIMUTHAL PROJECTIONS:

           -Jalon0/lat0/scale or -JAlon0/lat0/width (Lambert [E]).
                lon0/lat0 specifies the projection center.
                Give scale as 1:xxxx or radius/lat, where radius is distance
                in inch from origin to the oblique latitude lat.
           -Jelon0/lat0/scale or -JElon0/lat0/width (Equidistant).
                lon0/lat0 specifies the projection center.
                Give scale as 1:xxxx or radius/lat, where radius is distance
                in inch from origin to the oblique latitude lat.
           -Jflon0/lat0/horizon/scale or -JFlon0/lat0/horizon//width
           (Gnomonic).
                lon0/lat0 specifies the projection center.
                horizon specifies the max distance from projection center
           (in degrees, < 90).
                Give scale as 1:xxxx or radius/lat, where radius is distance
                in inch from origin to the oblique latitude lat.
           -Jglon0/lat0/scale or -JGlon0/lat0/width (Orthographic).
                lon0/lat0 specifies the projection center.
                Give scale as 1:xxxx or radius/lat, where radius is distance
                in inch from origin to the oblique latitude lat.
           -Jslon0/lat0/scale or -JSlon0/lat0/width (General Stereographic
           [C])
                lon0/lat0 specifies the projection center.
                Give scale as 1:xxxx or radius/lat, where radius is distance
                in inch from origin to the oblique latitude lat.

           CONIC PROJECTIONS:

           -Jblon0/lat0/lat1/lat2/scale or -JBlon0/lat0/lat1/lat2/width
           (Albers [E])
                Give projection center, two standard parallels, and scale
           (1:xxxx or inch/degree).
           -Jllon0/lat0/lat1/lat2/scale or -JLlon0/lat0/lat1/lat2/width
           (Lambert [C])
                Give origin, 2 standard parallels, and scale along these
           (1:xxxx or inch/degree).

           MISCELLANEOUS PROJECTIONS:

           -Jhlon0/scale or -JHlon0/width (Hammer [E])
                Give the central meridian and scale along equator (1:xxxx or
           inch/degree).
           -Jilon0/scale or -JIlon0/width (Sinusoidal [E])
                Give the central meridian and scale along equator (1:xxxx or
           inch/degree).
           -Jklon0/scale or -JKlon0/width (Eckert VI [E])
                Give the central meridian and scale along equator (1:xxxx or
           inch/degree).
           -Jnlon0/scale or -JNlon0/width (Robinson)
                Give the central meridian and scale along equator (1:xxxx or
           inch/degree).
           -Jrlon0/scale -JRlon0/width (Winkel Tripel)
                Give the central meridian and scale along equator (1:xxxx or
           inch/degree).
           -Jwlon0/scale or -JWlon0/width (Mollweide [E])
                Give the central meridian and scale along equator (1:xxxx or
           inch/degree).

           NON-GEOGRAPHICAL PROJECTIONS:

           -Jpscale or -JPwidth (Linear projection for polar (theta,r)
           coordinates)
                Give scale in inch/r-unit.
           -Jxx-scale[/y-scale] or -JXwidth[/height]
           scale [or width] can be any of the following 3 types:
                -Jxscale       - Regular linear scaling.
                -Jxscalel - Take log10 of values before scaling.
                -Jxscaleppower - Raise values to power before scaling.
           Give x-scale in inch/x-unit and y-scale in inch/y-unit.  (y-scale
           = x-scale if not specified separately).  Use negative scale(s) to
           reverse the direction of an axis (e.g., to have y be positive
           down).

           Append d if x and y are geographical coordinates in degrees.
           Default axes lengths (see gmtdefaults) can be invoked using -JXh
           (for landscape); -JXv (for portrait) will swap the x- and y-axes
           lengths.  The GMT default unit for this installation is inch.
           However, you may change this by editing your .gmtdefaults file(s)
           (run gmtdefaults to create one if you don't have it).
                The ellipsoid used in the map projections is user-definable
           by editing the .gmtdefaults file in your home directory.  13
           commonly used ellipsoids and a spheroid are currently supported,
           and users may also specify their own ellipsoid parameters (see
           man gmtdefaults for more details).  GMT default is WGS-84.

      -R   west, east, south, and north specify the Region of interest.  To
           specify boundaries in degrees and minutes [and seconds], use the
           dd:mm[:ss] format.  Append r if lower left and upper right map
           coordinates are given instead of wesn.

OPTIONS

      -E   Sets the viewpoint's azimuth and elevation (for perspective view)
           [180/90]

      -G   Paint inside of basemap. [Default is no fill].  Specify the shade
           (0-255) or color (r/g/b, each in 0-255).

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

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

      -L   Draws a simple map scale centered on lon0/lat0.  Use -Lx to
           specify position in inch instead.  Scale is calculated at
           latitude slat, 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].

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

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

      -U   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 in inch [Default is (-0.75i/-
           0.75i)].  Optionally, append a label, or c (which will plot the
           command string.)

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

      -X -Y
           Shift origin of plot by (x-shift,y-shift) inch  [Default is
           (a1i,a1i) for new plots, (0,0) for overlays].  Prepend a for
           absolute coordinates; the default (r) will reset plot origin.

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

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

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 in inch
      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", try

      psbasemap -R0/9/0/5 -Jx1 -Bf1a2:Distance:/:"No of samples":WeSn >
      linear.ps

log-log plot

      To make a log-log frame with only the left and bottom axes, where the
      x-axis is 9 inch and annotated every 1-2-5 and the y-axis is 6 inch
      and anotated every power of 10 but has tickmarks every 0.1, try

      psbasemap -R1/10000/1e20/1e25 -JX9il/6il
      -B2:Wavelength:/a1pf3:Power:WS > 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, try

      psbasemap -R0/100/0/5000 -Jx1p0.5/-0.001 -B1p:"Crustal
      age":/500:Depth: > 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
      every 30 degrees and 100 units, try

      psbasemap -R0/360/0/1000 -JP6i -B30p/100 > polar.ps

CYLINDRICAL MAP PROJECTIONS

Cassini

      A 4-inch-wide basemap using the Cassini projection may be obtained by

      psbasemap -R20/50/20/35 -JC35/28/4i -P -B5g5:.Cassini: > 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

      psbasemap -R90/180/-50/50 -Jm0.025i -B30g30:.Mercator: -Lx1i/1i/0/5000
      > mercator.ps

Miller

      A global Miller cylindrical map with scale 1:200,000,000, may be
      plotted as
      psbasemap -R0/360/-90/90 -Jj1:200000000 -B30g30:.Miller: > 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, try

      psbasemap  -R0/360/-70/70 -Joc0/0/90/30/0.025id -B30g30:."Oblique
      Mercator": > oblmerc.ps

Transverse Mercator [conformal]

      A regular Transverse Mercator basemap for some region may look like

      psbasemap -R69:30/71:45/-17/-15:15 -Jt70/1:1000000 -B15m:."Survey
      area": -P > transmerc.ps

Equidistant Cylindrical Projection

      This projection only needs the central meridian and scale.  A 9 inch
      wide global basemap centered on the 130E meridian is made by

      psbasemap -R-50/310/-90/90 -JQ130/9i -B30g30:."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

      psbasemap -R95/5/108/20r -Ju46/1:10000000 -B3g3:.UTM: > utm.ps

Basic 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 Peters projection.  A 9 inch wide global basemap
      centered on the Pacific is made by

      psbasemap -R0/360/-90/90 -JY180/45/9i -B30g30:.Peters: > peters.ps

CONIC MAP PROJECTIONS

Albers [equal-area]

      A basemap for middle Europe may be created by

      psbasemap -R0/90/25/55 -Jb45/20/32/45/0.1i -B10g10:."Albers Equal-
      area": > albers.ps

Lambert [conformal]

      Another basemap for middle Europe may be created by

      psbasemap -R0/90/25/55 -Jl45/20/32/45/0.1i -B10g10:."Lambert Conformal
      Conic": > lambertc.ps

AZIMUTHAL MAP PROJECTIONS

Lambert [equal-area]

      A 6-inch-wide global view of the world from the vantage point -80/-30
      will give the following basemap:

      psbasemap -R0/360-/-90/90 -JA-80/-30/6i -B30g30/15g15:."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 6-inch-wide global map in which distances from the center (here
      125/10) to any point is true can be obtained by:

      psbasemap -R0/360-/-90/90 -JE125/10/6i -B30g30/15g15:."Equidistant": >
      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:

      psbasemap -R0/360-/-90/90 -JF-100/40/60/6i -B30g30/15g15:."Gnomonic":
      > 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:

      psbasemap -R0/360-/-90/90 -JG125/10/6i -B30g30/15g15:."Orthographic":
      > ortho.ps

Stereographic [conformal]

      To make a Polar stereographic projection basemap with radius = 5 inch
      to -60 degree latitude, with plot title "Salinity measurements", using
      5 degrees annotation/tick interval and 1 degree gridlines, try

      psbasemap -R-45/45/-90/-60 -Js0/-90/5i/-60 -B5g1:."Salinity
      measurements": > stereo1.ps

      To make a 5-inch-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

      psbasemap -R100/-45/160/-5r -JS130/-30/5i -B30g30/15g15:."General
      Stereographic View": > stereo2.ps

MISCELLANEOUS MAP PROJECTIONS

Hammer [equal-aera]

      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, try

      psbasemap -R0/360/-90/90 -Jh180/1:200000000 -B30g30/15g15:.Hammer: >
      hammer.ps

Sinusoidal [equal-aera]

      To make a sinusiodal world map centered on Greenwich, with a scale
      along the equator of 0.02 inch/degree, try

      psbasemap -R0/360/-90/90 -Ji0/0.02i -B30g30/15g15:."Sinusoidal": >
      sinus1.ps

      To make an interrupted sinusiodal world map with breaks at 160W, 20W,
      and 60E, with a scale along the equator of 0.02 inch/degree, try the
      following sequence of commands:

      psbasemap -R-160/-20/-90/90 -Ji-90/0.02i -B30g30/15g15Wesn -K >
      sinus_i.ps
      psbasemap -R-20/60/-90/90 -Ji20/0.02i -B30g30/15g15wesn -O -K -X2.8i
      >> sinus_i.ps
      psbasemap -R60/200/-90/90 -Ji130/0.02i -B30g30/15g15wEsn -O -X1.6i >>
      sinus_i.ps

Eckert VI [equal-aera]

      Another pseudo-cylindrical projection typically used for global maps
      only.  Set the central longitude and scale, e.g.,

      psbasemap -R0/360/-90/90 -Jk180/0.025i -B30g30/15g15:."Eckert VI": >
      eckert4.ps

Robinson

      Projection designed to make global maps "look right".  Set the central
      longitude and width, e.g.,

      psbasemap -R-180/180/-90/90 -JN0/8i -B30g30/15g15:."Robinson": >
      robinson.ps

Winkel Tripel

      Yet another projection typically used for global maps only.  You can
      set the central longitude, e.g.,

      psbasemap -R90/450/-90/90 -JR270/9i -B30g30/15g15:."Winkel Tripel": >
      winkel.ps

Mollweide [equal-aera]

      The Mollweide projection is also mostly used for global maps and thus
      the spherical form is used.  To get a 10-inch-wide world map centered
      on the Dateline, try

      psbasemap -R0/360/-90/90 -JW180/10i -B30g30/15g15:.Mollweide: >
      mollweide.ps

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

      gmtdefaults, gmt