NAME

     psscale - Create grayscale or colorscale for maps


SYNOPSIS

     psscale  -Dxpos/ypos/length/width[h]  [   -Btickinfo   ]   [
     -Ccpt_file ] [ -E[length] ] [ -I[max_intens] ] [ -K ] [ -L ]
     [ -M ] [ -Ndpi ] [ -O ] [ -P ] [ -U[/dx/dy/][label] ]  [  -V
     ] [ -Xx-shift ] [ -Yy-shift ] [ -Zzfile ] [ -ccopies ]


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.

     -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   Set anotation, tick,  and  gridline  interval  for  the
          colorbar.  The xaxis label will plot beneath a horizon-
          tal bar (or vertically to the right of a vertical bar).
          As an option, use the yaxis label to plot the data unit
          to the right of a horizontal bar (and above a  vertical
          bar).   If  no  values  are provided, the default is to
          anotate every color level (which may be  overridden  by
          ULB  flags  in the cpt file).  Note that since vertical
          labels will be plotted as a column of individual  char-
          acters,  no  octal  escape  characters  imbedded in the
          label are allowed.

     -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 (but see -B).  If not  given,  psscale  will
          read stdin.

     -E   Add sidebar triangles for back- and foreground  colors.
          Optionally, append triangle height [Default is half the
          barwidth].

     -I   Add illumination effects.  Optionally, set the range of
          intensities  from + to - max_intens.  If not specified,
          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).

     -M   Force a monochrome graybar using the  (television)  YIQ
          transformation.

     -N   Effective dots-per-inch for the rectangular image  mak-
          ing up the color scale [300].

     -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.
          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).   Prepend  a
          for  absolute  coordinates;  the default (r) will reset
          plot origin.

     -Z   File with colorbar-width 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]


EXAMPLES

     To append a vertical colorscale (7.5 cm long; 1.25 cm  wide)
     to  the right of a plot that is 6 inch wide and 4 inch high,
     using illumination, and show back-  and  foreground  colors,
     and anotating every 5 units, try

     psscale   -D6.5i/2i/7.5c/1.25c   -O   -Ccolors.cpt   -I   -E
     -B5:BATHYMETRY:/:m: >> map.ps


SEE ALSO

     gmt(l), makecpt(l), grd2cpt(l)