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 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.  As  for  grdview,  psscale  can  understand  pattern
              specifications in the cpt file.

       -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). If set, any equal interval annotation set with
              -B will be ignored.

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

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

       -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     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

NOTES

       When the cpt file is discrete and no illumination is specified,  the  color  bar  will  be
       painted  using  polygons.  For  all  other  cases  we must paint with an image. Some color
       printers may give slightly different colors  for  the  two  methods  given  identical  RGB
       values.

SEE ALSO

       gmt(1gmt), makecpt(1gmt), grd2cpt(1gmt)

                                            1 Jan 2004                                 PSSCALE(l)