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 ] [ -Ndpi ] [ -O ] [ -P ] [
      -U[/dx/dy/][label] ] [ -V  ] [ -Xx-shift ] [ -Yy-shift ] [ -Zzfile ] [
      -ccopies ]

DESCRIPTION

      psscale plots grayscales or colorscales on maps.  Both horizontal 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 arguments.

      -B   Set anotation, tick, and gridline interval for the colorbar.  The
           xaxis label will plot beneath a horizontal 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 characters, 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 subset, 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).

      -N   Effective dots-per-inch for the rectangular image making 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 (-0.75i/-
           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   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]

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, and show back- and foreground colors, and anotating
      every 5 units, try

      psscale -D6.5i/2i/3i/0.5i -O -Ccolors.cpt -I -E -B5:BATHYMETRY:/:m: >>
      map.ps

SEE ALSO

      gmt, makecpt, grd2cpt