NAME

       psscale - Create grayscale or colorscale for maps

SYNOPSIS

       psscale -Dxpos/ypos/length/width[h]
        [  -A   ]  [  -Btickinfo  ]  [  -Ccpt_file  ]  [  -E[b|f][length]  ] [
       -I[max_intens] ] [ -K ] [ -L[i][gap] ] [ -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.

       -A     Place  annotations above (instead of below) horizontal scalebars
              and to the left (instead of the right) of vertical scalebars.

       -B     Set annotation, 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 annotate every color level (which may be overrid-
              den 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 embedded 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 annotated. To use a subset, add an extra col-
              umn to the cpt-file with a L, U, or B to annotate 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/or foreground colors. Add f
              or b for only one sidebar triangle [Default gives both]. 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.  If
              gap  is  appended  and  the cpt table is discrete we will center
              each annotation on each rectangle, using the lower  boundary  z-
              value  for  the  annotation.  If  i is prepended we annotate the
              interval range instead.

       -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.  Give
              c to center plot using current page size.

       -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  annotating  every  5
       units, use

       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)



GMT4.0                            1 Oct 2004                        PSSCALE(l)