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.  Varia-
       tions in intensity due to shading/illumination may be displayed by set-
       ting  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 verti-
              cal].


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 verti-
              cally 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.  Text  with
              such  characters  will  be plotted horizontally (relative to the
              color scale).

       -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 col-
              umn 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.  Option-
              ally, append triangle height [Default is half the barwidth].

       -I     Add illumination effects.  Optionally, set the range of intensi-
              ties  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  transfor-
              mation.

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

       -O     Selects Overlay plot mode [Default initializes a new  plot  sys-
              tem].

       -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  abso-
              lute 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  illumina-
       tion,  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(l), makecpt(l), grd2cpt(l)



VERSION                              DATE                           PSSCALE(l)

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