NAME

     psscale - Create grayscale or colorscale for maps


SYNOPSIS

     psscale -Ccpt_file -Dxpos/ypos/length/width[h] [ - Btickinfo
     ]  [ -Fred/green/blue ] [ -I[max_intens] ] [ -K ] [ -L ] [ -
     Ndpi ] [ -O ] [ -P ] [ -U[/dx/dy/][label] ] [ -V  ] [  - Xx-
     shift ] [ -Yy-shift ] [ -Zzfile ] [ -ccopies ] [ -0 || -1 ||
     -2 ]


DESCRIPTION

     psscale plots grayscales or colorscales on maps.  Both  hor-
     izontal  and  vertical  scales are supported.  For cpt_files
     with gradational colors (i.e., the lower and upper  boundary
     of  an  interval  have  different r/g/b values) psscale will
     interpolate to  give  a  continuous  scale.   Variations  in
     intensity  due  to  shading/illumination may be displayed by
     setting the option -I.  Colors may be spaced according to  a
     linear scale, all be equal size, or by providing a file with
     individual tile widths.

     -C    cpt_file is the color  palette  file  to  be  used  By
          default  all color changes are anotated.  To use a sub-
          set, add an extra column to the cpt-file with a  L,  U,
          or  B  to  anotate  Lower, Upper, or Both color segment
          boundaries.

     -D    Defines the position of the center/top (for horizontal
          scale)  or  center/left  (for  vertical  scale) and the
          dimensions of the scale.  Append h to get a  horizontal
          scale [Default is vertical].


OPTIONS

     No space between the option flag and  the  associated  argu-
     ments.

     -B    Here, only used to set the scale label and unit label,
          i.e.,  - B:"unit  label"::."Scale  label:".   Note that
          since vertical labels will be plotted as  a  column  of
          individual   characters,  no  octal  escape  characters
          imbedded in the label are allowed.

     - F    Sets  the  color  used  for  Frame  and  annotations.
          [Default is black]

     -I    Add illumination effects.  Optionally, set  the  range
          of intensities from + to - max_intens.  If not specify,
          1.0 is used.  [Default is no illumination]

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

     -L    Gives equal-sized color  rectangles.   Default  scales
          rectangles  according  to  the  z-range in the cpt-file
          (Also see -Z).

     -N    Effective dots-per-inch for the rectangular image mak-
          ing up the color scale [50].

     -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  (-0.75,-0.75)].   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 (1,1) for new plots, (0,0) for overlays].

     -Z    File with colorbar-width in inch per color entry.   By
          default, width of entry is scaled to color range, i.e.,
          z = 0-100 gives twice the width as z  =  100-150  (Also
          see -L).

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

     -0    Create the scale using the Adobe PostScript colorimage
          operator.   This is the GMT default (which can be modi-
          fied in the .gmtdefaults file).

     -1    Create the  scale  by  plotting  individually  colored
          tiles.

     -2    Create the scale by color separation using three calls
          to image for later processing by psto24.


EXAMPLES

     To append a vertical colorscale (3 inch long; 0.5 inch wide)
     to  the right of a plot that is 6 inch wide and 4 inch high,
     using illumination, try

     psscale -D6.5/2/3/0.5 -O -Ccolors.cpt -I - B:.BATHYMETRY::m:
     >> map.ps



SEE ALSO

     gmt, makecpt, grd2cpt


REFERENCES

     Wessel, P., and W. H. F. Smith, 1995,  The  Generic  Mapping
     Tools  (GMT)  version  3.0  Technical  Reference & Cookbook,
     SOEST/NOAA.
     Wessel, P., and W. H. F. Smith, 1995,  New  Version  of  the
     Generic Mapping Tools Released, EOS Trans. AGU, 76, p. 329.
     Wessel, P., and W. H. F. Smith, 1995,  New  Version  of  the
     Generic           Mapping           Tools          Released,
     http://www.agu.org/eos_elec/95154e.html, Copyright  1995  by
     the American Geophysical Union.
     Wessel, P., and W. H. F. Smith, 1991,  Free  Software  Helps
     Map and Display Data, EOS Trans. AGU, 72, p. 441.