Provided by: gmt-common_5.4.3+dfsg-1_all 
NAME
pslegend - Plot legends on maps
SYNOPSIS
pslegend [ specfile ]
-Drefpoint ] [ -B[p|s]parameters ] [ -Cdx/dy ] [ -Fbox ] [ -Jparameters ] [ -K ] [ -O ] [ -P ] [
-Rregion ] [ -U[stamp] ] [ -V[level] ] [ -Xx_offset ] [ -Yy_offset ] [ -pflags ] [ -ttransp ]
Note: No space is allowed between the option flag and the associated arguments.
DESCRIPTION
pslegend will make legends that can be overlaid on maps. It reads specific legend-related information
from an input file [or stdin]. Unless otherwise noted, annotations will be made using the primary
annotation font and size in effect (i.e., FONT_ANNOT_PRIMARY)
REQUIRED ARGUMENTS
-D[g|j|J|n|x]refpoint+wwidth[/height][+jjustify][+lspacing][+odx[/dy]]
Defines the reference point on the map for the legend using one of four coordinate systems: (1)
Use -Dg for map (user) coordinates, (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. Append +wwidth[/height] to set the width (and height) of the
legend box in plot coordinates (inches, cm, etc.). If height is zero or not given then we
estimate height based the expected vertical extent of the items to be placed. By default, the
anchor point on the legend 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. Use +lspacing to change the line-spacing factor in units of the
current font size [1.1]. 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).
OPTIONAL ARGUMENTS
-B[p|s]parameters (more …)
Set map boundary frame and axes attributes.
-Cdx/dy
Sets the clearance between the legend frame and the internal items [4p/4p].
-F[+cclearances][+gfill][+i[[gap/]pen]][+p[pen]][+r[radius]][+s[[dx/dy/][shade]]]
Without further options, draws a rectangular border around the legend using MAP_FRAME_PEN; specify
a different pen with +ppen. Add +gfill to fill the legend 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 values 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
relative to the foreground frame [4p/-4p] and shade sets the fill style to use for shading
[gray50].
-Jparameters (more …)
Select map projection.
-K (more …)
Do not finalize the PostScript plot.
-O (more …)
Append to existing PostScript plot.
-P (more …)
Select “Portrait” plot orientation.
-Rxmin/xmax/ymin/ymax[+r][+uunit] (more …)
Specify the region of interest.
-U[[just]/dx/dy/][c|label] (more …)
Draw GMT time stamp logo on plot.
-V[level] (more …)
Select verbosity level [c].
-X[a|c|f|r][x-shift[u]]
-Y[a|c|f|r][y-shift[u]] (more …)
Shift plot origin.
-p[x|y|z]azim[/elev[/zlevel]][+wlon0/lat0[/z0]][+vx0/y0] (more …)
Select perspective view.
-t[transp] (more …)
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 explanation 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.
PSLEGEND CODES
specfile
This ASCII file contains instructions for the layout of items in the legend. Each legend item is
described by a unique record. All records begin with a unique character that is common to all
records of the same kind. The order of the legend items is implied by the order of the records.
Fourteen different record types are recognized, and the syntax for each of these records are
presented below:
# comment
Records starting with # and blank lines are skipped.
A cptname
Symbol or cell color fills may be given indirectly via a z-value which can be used for the color
look-up via the given CPT cptname. You may switch to other cptname by repeating this command.
B cptname offset height [ optional arguments ]
The B record will plot a horizontal color bar, psscale-style in the middle, starting at offset
from the left edge, and of the given height. You may add any additional psscale options as well.
Any of the modifiers [+e[b|f][<length>]][+h][+ma|c|l|u][+n[<txt>]] may be given height. You may
add any additional psscale options as well. Any of the modifiers
[+e[b|f][length]][+h][+m[a|c|l|u]][+n[txt]] may be appended to the height argument, while other
module options -B -I -L -M -N -S -Z and -p may be appended as optional arguments at the end of the
record. See psscale for details on all modifiers and options.
C textcolor
The C record specifies the color with which the remaining text is to be printed. textcolor can be
in the form r/g/b, c/m/y/k, a named color, or an indirect color via z=value* (requires a prior
**A* code as well). Use - to reset to default color.
D [offset] pen [-|+|=]
The D record results in a horizontal line with specified pen across the legend with one quarter of
the line-spacing left blank above and below the line. Two gaps of offset units are left blank
between the horizontal line and the left and right frame sides [0]. If no pen is given we use
MAP_GRID_PEN_PRIMARY, and if pen is set to - then no visible line is drawn (we just remember the
location as a possible start/stop point for a vertical line; see V). To not add the quarter
line-spacing before the line, add -. To not add the spacing after the line, add +. For no
spacing at all, add = [Default places a quarter line-spacing both before and after the line].
F fill1 fill2 … filln
Specify fill (color of pattern) for cells. Alternatively, you can specify an indirect color via
z=value (requires a prior A code). If only fill1 is given then it is used to fill the entire row,
otherwise give one fill value for each active column (see N). If any fill is - then no fill takes
place [Default].
G gap The G record specifies a vertical gap of the given length. In addition to the standard units (i,
c, p) you may use l for lines. A negative gap will move the current line upwards (thus closing a
gap).
H fontsize|- font|- header
The H record plots a centered text string using the specified font parameters. Use - to default to
size and type of FONT_TITLE.
I imagefile width justification
Place an EPS or raster image in the legend justified relative to the current point. The image
width determines the size of the image on the page.
L fontsize|- font|- justification label
The L record plots a (L)eft, (C)entered, or (R)ight-justified text string within a column using
the specified font parameters. Use - to default to the size and type of FONT_LABEL.
M slon|- slat length [+f][+l[label]][+u] [-Fparam] [ -Rw/e/s/n -Jparam ]
Place a map scale in the legend. Specify slon slat, the point on the map where the scale applies
(slon is only meaningful for certain oblique projections. If not needed, you must specify -
instead). Give length, the length of the scale in km (for other units append e (meter), f (foot),
M (mile), n (nautical mile), or u (survey foot)). Append +f for a fancy map scale [Default is
plain]. Append +l to the length to select the default label which equals the distance unit
(meter, feet, km, miles, nautical miles, survey feet) and is justified on top of the scale [t].
Change this by giving your own label (append +llabel). Change label alignment with +aalign (choose
among l(eft), r(ight), t(op) , and b(ottom)). Apply +u to append the unit to all distance
annotations along the scale. If you want to place a map panel behind the scale, add a suitable -F
panel option (see psbasemap for details on panels as well as map scale modifiers). All +modifiers
must be appended to length to make a single string argument. If the -R -J supplied to pslegend is
different than the projection needed for the scale (or not given at all, e.g., with -Dx), supply
the two optional -R -J settings as well.
N [ncolumns or relwidth1 relwidth2 … relwidthn]
Change the number of columns in the legend [1]. This only affects the printing of symbols (S) and
labels (L). The number of columns stay in effect until N is used again. To get columns of unequal
width, instead provide the relative width of each column separated by whitespace. The sum of
these widths are equated to the legend width set via -D. If no argument is given the we set
n_columns to 1.
P paragraph-mode-header-for-pstext
Start a new text paragraph by specifying all the parameters needed (see pstext -M record
description). Note that pslegend knows what all those values should be, so normally you can leave
the entire record (after P) blank or leave it out all together. If you need to set at least one of
the parameters directly, you must specify all and set the ones you want to leave at their default
value to -.
S [dx1 symbol size fill pen [ dx2 text ]]
Plots the selected symbol with specified diameter, fill, and outline (see psxy). The symbol is
centered at dx1 from the left margin of the column, with the optional explanatory text starting
dx2 from the margin, printed with FONT_ANNOT_PRIMARY. Use - if no fill or outline (pen) is
required. Alternatively, the fill may be specified indirectly via z=value and the color is
assigned vi the CPT look-up (requires a prior A code). When plotting just a symbol, without text,
dx2 and text can be omitted. The dx1 value can also be given as a justification code L, C, R
which justifies the symbol with respect to the current column. If no arguments are given to S
then we simply skip to the next column. Three psxy symbols may take special modifiers: front (f),
quoted line (q) and vector (v). You can append modifiers to the symbol and affect how the
fronts, quoted lines and vectors are presented (see psxy man page for modifiers). pslegend will
determine default settings for all modifiers and secondary arguments if not provided. A few other
symbols (the rectangles, ellipse, wedge, mathangle) may take more than a single argument size.
Note that for a line segment you should use the horizontal dash symbol (-). If just a single size
if given then pslegend will provide reasonable arguments to plot the symbol (See Defaults).
Alternatively, combine the required arguments into a single, comma-separated string and use that
as the symbol size (again, see psxy for details on the arguments needed).
T paragraph-text
One or more of these T records with paragraph-text printed with FONT_ANNOT_PRIMARY. To specify
special positioning and typesetting arrangements, or to enter a paragraph break, use the optional
P record.
V [offset] pen
The V record draws a vertical line between columns (if more than one) using the selected pen.
Here, offset is analogous to the offset for the D records but in the vertical direction [0]. The
first time V is used we remember the vertical position of the last D line, and the second time V
is set we draw from that past location to the most recent location of the D line. Thus, D must be
used to mark the start and stop of a vertical line (so V must follow D). If no horizontal line is
desired simply give - as pen to D.
DEFAULTS
When attributes are not provided, or extended symbol information (for symbols taking more than just an
overall size) are not given as comma-separated quantities, pslegend will provide the following defaults:
Front: Front symbol is left-side (here, that means upper side) box, with dimensions 30% of the given
symbol size.
Vector: Head size is 30% of given symbol size.
Ellipse: Minor axis is 65% of major axis (the symbol size), with an azimuth of 0 degrees.
Rectangle: Height is 65% of width (the symbol size).
Rotated rectangle: Same, with a rotation of 30 degrees.
Rounded rectangle: Same as rectangle, but with corner radius of 10% of width.
Mathangle: Angles are -10 and 45 degrees, with arrow head size 30% of symbol size.
Wedge: Angles are -30 and 30 degrees.
EXAMPLES
To add an example of a legend to a Mercator plot (map.ps) with the given specifications, use
gmt pslegend -R-10/10/-10/10 -JM6i -F+gazure1 -Dx0.5i/0.5i+w5i/3.3i+jBL+l1.2 \
-C0.1i/0.1i -B5f1 << EOF >> map.ps
# Legend test for pslegend
# G is vertical gap, V is vertical line, N sets # of columns, D draws horizontal line.
# H is header, L is label, S is symbol, T is paragraph text, M is map scale.
#
G -0.1i
H 24 Times-Roman My Map Legend
D 0.2i 1p
N 2
V 0 1p
S 0.1i c 0.15i p300/12 0.25p 0.3i This circle is hachured
S 0.1i e 0.15i yellow 0.25p 0.3i This ellipse is yellow
S 0.1i w 0.15i green 0.25p 0.3i This wedge is green
S 0.1i f0.1i+l+t 0.25i blue 0.25p 0.3i This is a fault
S 0.1i - 0.15i - 0.25p,- 0.3i A dashed contour
S 0.1i v0.1i+a40+e 0.25i magenta 0.25p 0.3i This is a vector
S 0.1i i 0.15i cyan 0.25p 0.3i This triangle is boring
V 0 1p
D 0.2i 1p
N 1
M 5 5 600+u f
G 0.05i
I SOEST_logo.ras 3i CT
G 0.05i
B colors.cpt 0.2i 0.2i
G 0.05i L 9 4 R Smith et al., @%5%J. Geophys. Res., 99@%%, 2000
G 0.1i
P
T Let us just try some simple text that can go on a few lines.
T There is no easy way to predetermine how many lines will be required,
T so we may have to adjust the box height to get the right size box.
EOF
NOTE ON LEGEND HEIGHT
As -D suggests, leaving the height off forces a calculation of the expected height. This is an exact
calculation except in the case of legends that place paragraph text. Here we simply do a first-order
estimate of how many typeset lines might appear. Without access to font metrics this estimate will
occasionally be off by 1 line. If so, note the reported height (with -V) and specify a slightly larger or
smaller height in -D.
WINDOWS REMARKS
Note that under Windows, the percent sign (%) is a variable indicator (like $ under Unix). To indicate a
plain percentage sign in a batch script you need to repeat it (%%); hence the font switching mechanism
(@%font% and @%%) may require twice the number of percent signs. This only applies to text inside a
script or that otherwise is processed by DOS. Data files that are opened and read by pslegend do not need
such duplication.
SEE ALSO
gmt, gmt.conf, gmtcolors, gmtlogo psbasemap, pstext, psxy
COPYRIGHT
2018, P. Wessel, W. H. F. Smith, R. Scharroo, J. Luis, and F. Wobbe