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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|k]  ]  [  -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. See psbasemap for details.

       -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), else the scale argument(s) is
              the map scale (see its definition for each projection). UNIT is  cm,  inch,  or  m,
              depending  on  the MEASURE_UNIT setting in .gmtdefaults, but this can be overridden
              on the command line by appending c, i, or m to the scale/width values.  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 UNIT/degree).
              -Jjlon0/scale or -JJlon0/width (Miller Cylindrical Projection).
                      Give the central meridian and scale (1:xxxx or UNIT/degree).
              -Jmparameters (Mercator [C]). Specify one of:
                      -Jmscale or -JMwidth
                              Give scale along equator (1:xxxx or UNIT/degree).
                      -Jmlon0/lat0/scale or -JMlon0/lat0/width
                              Give central meridian, standard latitude and scale  along  parallel
              (1:xxxx or UNIT/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 UNIT/degree).
              -Jqlon0/scale or -JQlon0/width (Equidistant Cylindrical Projection (Plate Carree)).
                      Give the central meridian and scale (1:xxxx or UNIT/degree).
              -Jtparameters (Transverse Mercator [C]). Specify one of:
                      -Jtlon0/scale or -JTlon0/width
                              Give the central meridian and scale (1:xxxx or UNIT/degree).
                      -Jtlon0/lat0/scale or -JTlon0/lat0/width
                              Give projection center and scale (1:xxxx or UNIT/degree).
              -Juzone/scale or -JUzone/width (UTM - Universal Transverse Mercator [C]).
                      Give the zone number (1-60) and scale (1:xxxx or UNIT/degree).
                      zones:  prepend  -  or  +  to  enforce  southern  or  northern   hemisphere
              conventions [northern if south > 0].
              -Jylon0/lats/scale or -JYlon0/lats/width (Basic Cylindrical Projections [E]).
                      Give  the  central  meridian,  standard  parallel,  and  scale  (1:xxxx  or
              UNIT/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 UNIT 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 UNIT 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 UNIT 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 UNIT 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  (true  at  pole)  or slat/1:xxxx (true at standard
              parallel slat)
                      or radius/lat (radius in UNIT 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
              UNIT/degree).
              -Jdlon0/lat0/lat1/lat2/scale or -JDlon0/lat0/lat1/lat2/width (Equidistant)
                      Give  projection  center,  two  standard  parallels,  and  scale (1:xxxx or
              UNIT/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
              UNIT/degree).

              MISCELLANEOUS PROJECTIONS:

              -Jhlon0/scale or -JHlon0/width (Hammer [E]).
                      Give the central meridian and scale along equator (1:xxxx or UNIT/degree).
              -Jilon0/scale or -JIlon0/width (Sinusoidal [E]).
                      Give the central meridian and scale along equator (1:xxxx or UNIT/degree).
              -Jk[f|s]lon0/scale or -JK[f|s]lon0/width (Eckert IV (f) and VI (s) [E]).
                      Give the central meridian and scale along equator (1:xxxx or UNIT/degree).
              -Jnlon0/scale or -JNlon0/width (Robinson).
                      Give the central meridian and scale along equator (1:xxxx or UNIT/degree).
              -Jrlon0/scale -JRlon0/width (Winkel Tripel).
                      Give the central meridian and scale along equator (1:xxxx or UNIT/degree).
              -Jvlon0/scale or -JVlon0/width (Van der Grinten).
                      Give the central meridian and scale along equator (1:xxxx or UNIT/degree).
              -Jwlon0/scale or -JWlon0/width (Mollweide [E]).
                      Give the central meridian and scale along equator (1:xxxx or UNIT/degree).

              NON-GEOGRAPHICAL PROJECTIONS:

              -Jp[a]scale[/origin] or -JP[a]width[/origin] (Linear projection for polar (theta,r)
              coordinates, optionally insert a after -Jp [ or -JP] for  azimuths  CW  from  North
              instead of directions CCW from East [default], optionally append /origin in degrees
              to indicate an angular offset [0]).
                      Give scale in UNIT/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 UNIT/x-unit and y-scale in UNIT/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 a single d if data 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  UNIT.  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. Several
              GMT parameters can affect the projection: ELLIPSOID, INTERPOLANT, MAP_SCALE_FACTOR,
              and MEASURE_UNIT; see the gmtdefaults man page for details.

       -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  x/y  position
              iinstead.   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].

       -bo    Selects binary output. Append s for single precision [Default is double].

       -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.
              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.

       -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).  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
       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 25 cm and
       annotated every 1-2-5 and the y-axis is 15 cm and anotated  every  power  of  10  but  has
       tickmarks every 0.1, try

       psbasemap -R1/10000/1e20/1e25 -JX25cl/15cl -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 10 -cm-wide basemap using the Cassini projection may be obtained by

       psbasemap -R20/50/20/35 -JC35/28/10c -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 -Joc0/0/90/30/0.064cd -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 25 cm wide global basemap
       centered on the 130E meridian is made by

       psbasemap -R-50/310/-90/90 -JQ130/25c -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 -Jb45/20/32/45/0.25c -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

Equidistant

       Yet another basemap of width 6 inch for middle Europe may be created by

       psbasemap -R0/90/25/55 -JD45/20/32/45/6i -B10g10:."Equidistant conic": > econic.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:

       psbasemap -R0/360-/-90/90 -JA-80/-30/15c -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 15 -cm-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 -JE125/10/15c -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 = 12 cm 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/-90/12c/-60 -B5g1:."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

       psbasemap  -R100/-45/160/-5r -JS130/-30/12c -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 IVI [equal-aera]

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

       psbasemap -R0/360/-90/90 -Jkf180/0.064c -B30g30/15g15:."Eckert IV": > eckert4.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 -Jks180/0.064c -B30g30/15g15:."Eckert VI": > eckert6.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 -JR270/25c -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 25 -cm-wide world map centered on the Dateline, try

       psbasemap -R0/360/-90/90 -JW180/25c -B30g30/15g15:.Mollweide: > 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 10 -inch-wide world map centered on the Dateline, try

       psbasemap -R0/360/-90/90 -JV180/10i -B30g30/15g15:."Van der Grinten": > grinten.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(1gmt), gmt(1gmt)

                                            1 Jan 2004                               PSBASEMAP(l)