psscale(1) GMT psscale(1)
NAME
psscale - Plot a gray or color scale-bar on maps
SYNOPSIS
psscale -Drefpoint [ -B[p|s]parameters ] [ -Ccpt ] [ -Fbox ] [
-Gzlo/zhi ] [ -I[max_intens|low_i/high_i] ] [ -Jparameters ] [
-Jz|Zparameters ] [ -K ] [ -L[i][gap] ] [ -M ] [ -N[p|dpi ]] [ -O
] [ -P ] [ -Q ] [ -Rregion ] [ -S ] [ -U[stamp] ] [ -V[level] ] [
-Wscale ] [ -Xx_offset ] [ -Yy_offset ] [ -Zzfile ] [ -pflags ] [
-ttransp ]
Note: No space is allowed between the option flag and the associated
arguments.
DESCRIPTION
psscale plots gray scales or color scales on maps. Both horizontal and
vertical scales are supported. For CPTs with gradational colors (i.e.,
the lower and upper boundary of an interval have different colors) pss-
cale will interpolate to give a continuous scale. Variations in inten-
sity 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. The font used
for the annotations along the scale and optional units is specified by
FONT_ANNOT_PRIMARY. If a label is requested, it is plotted with
FONT_LABEL.
REQUIRED ARGUMENTS
-D[g|j|J|n|x]refpoint[+wlength[/width]][+e[b|f][length]][+h|v][+jjus-
tify][+m[a|c|l|u]][+n[txt]][+odx[/dy]]
Defines the reference point on the map for the color scale using
one of four coordinate systems: (1) Use -Dg for map (user) coor-
dinates, (2) use -Dj or -DJ for setting refpoint via a 2-char
justification code that refers to the (invisible) map domain
rectangle, (3) use -Dn for normalized (0-1) coordinates, or (4)
use -Dx for plot coordinates (inches, cm, etc.). All but -Dx
requires both -R and -J to be specified. For -Dj or -DJ with
codes TC, BC, ML, MR (i.e., centered on one of the map sides) we
pre-calculate all further settings. Specifically, the length is
set to 80% of the map side, horizontal or vertical depends on
the side, the offset is MAP_LABEL_OFFSET for Dj with an extra
offset MAP_FRAME_WIDTH for DJ, and annotations are placed on the
side of the scale facing away from the map frame. However, you
can override any of these with these modifiers: Append +w fol-
lowed by the length and width of the color bar. If width is not
specified then it is set to 4% of the given length. Give a neg-
ative length to reverse the scale bar. Append +h to get a hori-
zontal scale [Default is vertical (+v)]. By default, the anchor
point on the scale is assumed to be the bottom left corner (BL),
but this can be changed by appending +j followed by a 2-char
justification code justify (see pstext). Note: If -Dj is used
then justify defaults to the same as refpoint, if -DJ is used
then justify defaults to the mirror opposite of refpoint.
Finally, add +o to offset the color scale by dx/dy away from the
refpoint point in the direction implied by justify (or the
direction implied by -Dj or -DJ). Add sidebar triangles for
back- and/or foreground colors with +e. Append f (foreground) or
b (background) for only one sidebar triangle [Default gives
both]. Optionally, append triangle height [Default is half the
barwidth]. Move text to opposite side with +m[a|c|l|u]. Hori-
zontal scale bars: Move annotations and labels above the scale
bar [Default is below]; the unit remains on the left. Vertical
scale bars: Move annotations and labels to the left of the scale
bar [Default is to the right]; the unit remains below. Append
one or more of a, l or u to control which of the annotations,
label, and unit that will be moved to the opposite side. Append
c if you want to print a vertical label as a column of charac-
ters (does not work with special characters). Append +n to plot
a rectangle with the NaN color at the start of the bar, append
text to change label from NaN.
OPTIONAL ARGUMENTS
-B[p|s]parameters
Set annotation, tick, and gridline interval for the colorbar.
The x-axis label will plot beneath a horizontal bar (or verti-
cally to the right of a vertical bar), except when using -A. As
an option, use the y-axis label to plot the data unit to the
right of a horizontal bar (and above a vertical bar). When using
-Ba or -Baf annotation and/or minor tick intervals are chosen
automatically. If -B is omitted, or no annotation intervals are
provided, the default is to annotate every color level based on
the numerical entries in the CPT (which may be overridden by ULB
flags in the CPT). To specify custom text annotations for inter-
vals, you must append ;annotation to each z-slice in the CPT.
-Ccpt cpt is the CPT to be used. By default all color changes are
annotated. To use a subset, add an extra column to the CPT 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.
Like grdview, psscale can understand pattern specifications in
the CPT. For CPTs where the z range is in meters, it may be use-
ful to change to another unit when plotting. To do so, append
+Uunit to the file name. Likewise, if the CPT uses another unit
than meter and you wish to plot the CPT versus meters, append
+uunit. If a GMT master dynamic CPT is given instead then its
z-range will be set to its default range (if it has one) before
plotting.
-F[+cclear-
ances][+gfill][+i[[gap/]pen]][+p[pen]][+r[radius]][+s[[dx/dy/][shade]]]
Without further options, draws a rectangular border around the
scale using MAP_FRAME_PEN; specify a different pen with +ppen.
Add +gfill to fill the scale box [no fill]. Append +cclearance
where clearance is either gap, xgap/ygap, or lgap/rgap/bgap/tgap
where these items are uniform, separate in x- and y-direction,
or individual side spacings between scale and border. Append +i
to draw a secondary, inner border as well. We use a uniform gap
between borders of 2p and the MAP_DEFAULTS_PEN unless other val-
ues are specified. Append +r to draw rounded rectangular borders
instead, with a 6p corner radius. You can override this radius
by appending another value. Finally, append +s to draw an offset
background shaded region. Here, dx/dy indicates the shift rela-
tive to the foreground frame [4p/-4p] and shade sets the fill
style to use for shading [gray50].
-Gzlo/zhi
Truncate the incoming CPT so that the lowest and highest z-lev-
els are to zlo and zhi. If one of these equal NaN then we leave
that end of the CPT alone. The truncation takes place before
the plotting.
-I[max_intens|low_i/high_i]
Add illumination effects. Optionally, set the range of intensi-
ties from - to + max_intens. If not specified, 1 is used.
Alternatively, append low/high intensities to specify an asym-
metric range [Default is no illumination].
-Jparameters (more a|)
Select map projection.
-Jz|Zparameters (more a|)
Set z-axis scaling; same syntax as -Jx.
-K (more a|)
Do not finalize the PostScript plot.
-L[i][gap]
Gives equal-sized color rectangles. Default scales rectangles
according to the z-range in the CPT (Also see -Z). If set, any
equal interval annotation set with -B will be ignored. If gap is
appended and the CPT 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. If -I is used then each rectangle will have its con-
stant color modified by the specified intensity.
-M Force a monochrome graybar using the (television) YIQ transfor-
mation.
-N[p|dpi]
Controls how the color scale is represented by the PostScript
language. To preferentially draw color rectangles (e.g., for
discrete colors), append p. Otherwise we will preferentially
draw images (e.g., for continuous colors). Optionally append
effective dots-per-inch for rasterization of color scales [600].
-O (more a|)
Append to existing PostScript plot.
-P (more a|)
Select aPortraita plot orientation.
-Q Select logarithmic scale and power of ten annotations. All
z-values in the CPT will be converted to p = log10(z) and only
integer p values will be annotated using the 10^p format
[Default is linear scale].
-Rwest/east/south/north[/zmin/zmax][+r][+uunit]
west, east, south, and north specify the region of interest, and
you may specify them in decimal degrees or in
[A+-]dd:mm[:ss.xxx][W|E|S|N] format Append +r if lower left and
upper right map coordinates are given instead of w/e/s/n. The
two shorthands -Rg and -Rd stand for global domain (0/360 and
-180/+180 in longitude respectively, with -90/+90 in latitude).
Alternatively for grid creation, give Rcodelon/lat/nx/ny, where
code is a 2-character combination of L, C, R (for left, center,
or right) and T, M, B for top, middle, or bottom. e.g., BL for
lower left. This indicates which point on a rectangular region
the lon/lat coordinate refers to, and the grid dimensions nx and
ny with grid spacings via -I is used to create the corresponding
region. Alternatively, specify the name of an existing grid
file and the -R settings (and grid spacing, if applicable) are
copied from the grid. Appending +uunit expects projected (Carte-
sian) coordinates compatible with chosen -J and we inversely
project to determine actual rectangular geographic region. For
perspective view (-p), optionally append /zmin/zmax. In case of
perspective view (-p), a z-range (zmin, zmax) can be appended to
indicate the third dimension. This needs to be done only when
using the -Jz option, not when using only the -p option. In the
latter case a perspective view of the plane is plotted, with no
third dimension.
For perspective view p, optionally append /zmin/zmax. (more a|)
-S Do not separate different color intervals with black grid lines.
-U[[just]/dx/dy/][c|label] (more a|)
Draw GMT time stamp logo on plot.
-V[level] (more a|)
Select verbosity level [c].
-Wscale
Multiply all z-values in the CPT by the provided scale. By
default the CPT is used as is.
-X[a|c|f|r][x-shift[u]]
-Y[a|c|f|r][y-shift[u]] (more a|)
Shift plot origin.
-Zzfile
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).
-p[x|y|z]azim[/elev[/zlevel]][+wlon0/lat0[/z0]][+vx0/y0] (more a|)
Select perspective view. (Required -R and -J for proper func-
tioning).
-t[transp] (more a|)
Set PDF transparency level in percent.
-^ or just -
Print a short message about the syntax of the command, then
exits (NOTE: on Windows just use -).
-+ or just +
Print an extensive usage (help) message, including the explana-
tion of any module-specific option (but not the GMT common
options), then exits.
-? or no arguments
Print a complete usage (help) message, including the explanation
of all options, then exits.
EXAMPLES
To plot a a horizontal color scale (12 cm long; 0.5 cm wide) at the
reference point (8,1) (paper coordinates) with justification at top
center and automatic annotation interval, do
gmt makecpt -T-200/1000/100 -Crainbow > t.cpt
gmt psscale -Ct.cpt -Dx8c/1c+w12c/0.5c+jTC+h -Bxaf+l"topography" -By+lkm > map.ps
To append a vertical color scale (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, we provide the reference point and select the left-mid anchor
point via
gmt psscale -Dx6.5i+jLM/2i+w7.5c/1.25c+e -O -Ccolors.cpt -I -Bx5+lBATHYMETRY -By+lm >> map.ps
To overlay a horizontal color scale (4 inches long and default width)
above a Mercator map produced by a previous call, ensuring a 2 cm off-
set from the map frame, use
gmt psscale -DjCT+w4i+o0/2c+h -O -Ccolors.cpt -Baf -R -J >> map.ps
NOTES
When the CPT 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(1), makecpt(1), gmtlogo(1), grd2cpt(1), psimage(1), pslegend(1)
COPYRIGHT
2017, P. Wessel, W. H. F. Smith, R. Scharroo, J. Luis, and F. Wobbe
5.4.2 Jun 24, 2017 psscale(1)
gmt5 5.4.2 - Generated Thu Jun 29 15:46:23 CDT 2017