NAME
psclip - To set up polygonal clip paths
SYNOPSIS
psclip xyfiles -Jparameters -Rwest/east/south/north[r] [
-Btickinfo ] [ -Eaz/el ] [ -K ] [ -N ] [ -M[flag] ] [ -O ] [
-P ] [ -U[/dx/dy/][label] ] [ -V ] [ -Xx-shift ] [ -Yy-shift
] [ -Zzlevel ] [ -ccopies ] [ -: ] [ -bi[s][n] ]
psclip -C [ -K ] [ -O ]
DESCRIPTION
psclip reads (x,y) file(s) [or standard input] and draws
polygons that are activated as clipping paths. Several
files may be read to create complex paths consisting of
several non-connecting segments. As an option (-N), the
user may choose to reverse the sense of what is the inside
and outside of the paths. After subsequent plotting, which
will be clipped against these paths, the clipping may be
deactivated by running psclip a second time with the -C
option only.
xyfiles
ASCII [or binary, see -b] file(s) with (x,y) values for
clip polygons. If no files are given, the standard
input is read.
-C Mark end of existing clip path. No input file or pro-
jection information are needed.
-J Selects the map projection. Scale is UNIT/degree,
1:xxxxx, or width in UNIT (upper case modifier). UNIT
is cm, inch, or m, depending on the MEASURE_UNIT set-
ting in .gmtdefaults, but this can be overridden on the
command line by appending the c, i, or m to the
scale/width value.
CYLINDRICAL PROJECTIONS:
-Jclon0/lat0/scale (Cassini)
-Jjlon0/scale (Miller)
-Jmscale (Mercator - Greenwich and Equator as origin)
-Jmlon0/lat0/scale (Mercator - Give meridian and stan-
dard parallel)
-Joalon0/lat0/azimuth/scale (Oblique Mercator - point
and azimuth)
-Joblon0/lat0/lon1/lat1/scale (Oblique Mercator - two
points)
-Joclon0/lat0/lonp/latp/scale (Oblique Mercator - point
and pole)
-Jqlon0/scale (Equidistant Cylindrical Projection
(Plate Carree))
-Jtlon0/scale (TM - Transverse Mercator, with Equator
as y = 0)
-Jtlon0/lat0/scale (TM - Transverse Mercator, set ori-
gin)
-Juzone/scale (UTM - Universal Transverse Mercator)
-Jylon0/lats/scale (Basic Cylindrical Projection)
AZIMUTHAL PROJECTIONS:
-Jalon0/lat0/scale (Lambert).
-Jelon0/lat0/scale (Equidistant).
-Jflon0/lat0/horizon/scale (Gnomonic).
-Jglon0/lat0/scale (Orthographic).
-Jslon0/lat0/scale (General Stereographic)
CONIC PROJECTIONS:
-Jblon0/lat0/lat1/lat2/scale (Albers)
-Jdlon0/lat0/lat1/lat2/scale (Equidistant)
-Jllon0/lat0/lat1/lat2/scale (Lambert)
MISCELLANEOUS PROJECTIONS:
-Jhlon0/scale (Hammer)
-Jilon0/scale (Sinusoidal)
-Jk[f|s]lon0/scale (Eckert IV (f) and VI (s))
-Jnlon0/scale (Robinson)
-Jrlon0/scale (Winkel Tripel)
-Jvlon0/scale (Van der Grinten)
-Jwlon0/scale (Mollweide)
NON-GEOGRAPHICAL PROJECTIONS:
-Jpscale[/origin] (polar (theta,r) coordinates, option-
ally offset theta [0])
-Jxx-scale[l|ppow][/y-scale[l|ppow]] (Linear, log, and
power scaling)
More details can be found in the psbasemap manpages.
-R west, east, south, and north specify the Region of
interest. To specify boundaries in degrees and minutes
[and seconds], use the dd:mm[:ss] format. Append r if
lower left and upper right map coordinates are given
instead of wesn.
OPTIONS
No space between the option flag and the associated argu-
ments
-B Sets map boundary tickmark intervals. See psbasemap for
details.
-E Sets the viewpoint's azimuth and elevation [180/90]
-H Input file(s) has Header record(s). Number of header
records can be changed by editing your .gmtdefaults
file. If used, GMT default is 1 header record.
-K More PostScript code will be appended later [Default
terminates the plot system].
-M Multiple segment file. Segments are separated by a
record whose first character is <flag>. [Default is
'>'].
-N Invert the sense of what is inside and outside, i.e.,
use the outside of the polygons for clipping.
-O Selects Overlay plot mode [Default initializes a new
plot system].
-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.)
-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 For 3-D projections: Sets the z-level of the polygons
[0].
-: Toggles between (longitude,latitude) and
(latitude,longitude) input/output. [Default is
(longitude,latitude)].
-c Specifies the number of plot copies. [Default is 1]
-bi Selects binary input. Append s for single precision
[Default is double]. Append n for the number of
columns in the binary file(s). [Default is 2 input
columns].
EXAMPLES
To make an overlay PostScript file that will set up a
complex clip area to which subsequent plotting will be con-
fined to, try:
psclip my_region.xy -R0/40/0/40 -Jm0.3i -O -K >
clip_mask_on.ps
To deactivate the clipping in an existing plotfile, run:
psclip -C -O >> complex_plot.ps
SEE ALSO
gmt(l), grdmask(l), psbasemap(l), psmask(l)