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 ] [
-Z zlevel ] [
-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 projection 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 setting 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 standard
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 origin)
-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/[slat/]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:
-Jp[a]scale[/origin] (polar (theta,r)
coordinates, optional a for azimuths and 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 arguments
- -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.
- -bo
- Selects binary output. Append s for single precision [Default is
double].
- -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
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)]. Applies to geographic
coordinates only.
- -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 confined to, try:
psclip my_region.xy
-R0/40/0/40
-Jm0.3
i -O -K >
clip_mask_on.ps
To deactivate the clipping in an existing plotfile, run:
psclip
-C -O >> complex_plot.ps
BUGS¶
psclip cannot handle polygons that contain the south or north pole. For
such polygons, you should split them into two and make each explicitly contain
the polar point. The two clip polygons will combine to give the desired
effect.
SEE ALSO¶
gmt(1gmt),
grdmask(1gmt),
psbasemap(1gmt),
psmask(1gmt)