1PSCLIP(1) Generic Mapping Tools PSCLIP(1)
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6 psclip - To set up polygonal clip paths
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9 psclip xyfiles -Jparameters -Rwest/east/south/north[r] [ -B[p|s]parame‐
10 ters ] [ -Eazim/elev ] [ -K ] [ -N ] [ -M[flag] ] [ -O ] [ -P ] [
11 -U[just/dx/dy/][c|label] ] [ -V ] [ -X[a|c|r][x-shift[u]] ] [
12 -Y[a|c|r][y-shift[u]] ] [ -Zzlevel ] [ -ccopies] [ -:[i|o] ] [
13 -bi[s|S|d|D[ncol]|c[var1/...]] ] [ -fcolinfo ]
14 psclip -C [ -K ] [ -O ]
16
18 psclip reads (x,y) file(s) [or standard input] and draws polygons that
19 are activated as clipping paths. Several files may be read to create
20 complex paths consisting of several non-connecting segments. As an
21 option (-N), the user may choose to reverse the sense of what is the
22 inside and outside of the paths. After subsequent plotting, which will
23 be clipped against these paths, the clipping may be deactivated by run‐
24 ning psclip a second time with the -C option only.
25 xyfiles
27 ASCII [or binary, see -b] file(s) with (x,y) values for clip
28 polygons. If no files are given, the standard input is read.
29 -C Mark end of existing clip path. No input file or projection
31 information are needed.
32 -J Selects the map projection. Scale is UNIT/degree, 1:xxxxx, or
34 width in UNIT (upper case modifier). UNIT is cm, inch, or m,
35 depending on the MEASURE_UNIT setting in .gmtdefaults4, but this
36 can be overridden on the command line by appending c, i, or m to
37 the scale/width value. When central meridian is optional,
38 default is center of longitude range on -R option. Default
39 standard parallel is the equator. For map height, max dimen‐
40 sion, or min dimension, append h, +, or - to the width, respec‐
41 tively.
42 More details can be found in the psbasemap man pages.
43 CYLINDRICAL PROJECTIONS:
45 -Jclon0/lat0/scale (Cassini)
47 -Jcyl_stere/[lon0/[lat0/]]scale (Cylindrical Stereographic)
48 -Jj[lon0/]scale (Miller)
49 -Jm[lon0/[lat0/]]scale (Mercator)
50 -Jmlon0/lat0/scale (Mercator - Give meridian and standard paral‐
51 lel)
52 -Jo[a]lon0/lat0/azimuth/scale (Oblique Mercator - point and
53 azimuth)
54 -Jo[b]lon0/lat0/lon1/lat1/scale (Oblique Mercator - two points)
55 -Joclon0/lat0/lonp/latp/scale (Oblique Mercator - point and
56 pole)
57 -Jq[lon0/[lat0/]]scale (Cylindrical Equidistant)
58 -Jtlon0/[lat0/]scale (TM - Transverse Mercator)
59 -Juzone/scale (UTM - Universal Transverse Mercator)
60 -Jy[lon0/[lat0/]]scale (Cylindrical Equal-Area)
61 CONIC PROJECTIONS:
63 -Jblon0/lat0/lat1/lat2/scale (Albers)
65 -Jdlon0/lat0/lat1/lat2/scale (Conic Equidistant)
66 -Jllon0/lat0/lat1/lat2/scale (Lambert Conic Conformal)
67 AZIMUTHAL PROJECTIONS:
69 -Jalon0/lat0[/horizon]/scale (Lambert Azimuthal Equal-Area)
71 -Jelon0/lat0[/horizon]/scale (Azimuthal Equidistant)
72 -Jflon0/lat0[/horizon]/scale (Gnomonic)
73 -Jglon0/lat0[/horizon]/scale (Orthographic)
74 -Jglon0/lat0/altitude/azimuth/tilt/twist/Width/Height/scale
75 (General Perspective).
76 -Jslon0/lat0[/horizon][/slat]/scale (General Stereographic)
77 MISCELLANEOUS PROJECTIONS:
79 -Jh[lon0/]scale (Hammer)
81 -Ji[lon0/]scale (Sinusoidal)
82 -Jkf[lon0/]scale (Eckert IV)
83 -Jk[s][lon0/]scale (Eckert IV)
84 -Jn[lon0/]scale (Robinson)
85 -Jr[lon0/]scale (Winkel Tripel)
86 -Jv[lon0/]scale (Van der Grinten)
87 -Jw[lon0/]scale (Mollweide)
88 NON-GEOGRAPHICAL PROJECTIONS:
90 -Jp[a]scale[/origin][r|z] (Polar coordinates (theta,r))
92 -Jxx-scale[d|l|ppow|t|T][/y-scale[d|l|ppow|t|T]] (Linear, log,
93 and power scaling)
94 -R xmin, xmax, ymin, and ymax specify the Region of interest. For
96 geographic regions, these limits correspond to west, east,
97 south, and north and you may specify them in decimal degrees or
98 in [+-]dd:mm[:ss.xxx][W|E|S|N] format. Append r if lower left
99 and upper right map coordinates are given instead of w/e/s/n.
100 The two shorthands -Rg and -Rd stand for global domain (0/360
101 and -180/+180 in longitude respectively, with -90/+90 in lati‐
102 tude). For calendar time coordinates you may either give (a)
103 relative time (relative to the selected TIME_EPOCH and in the
104 selected TIME_UNIT; append t to -JX|x), or (b) absolute time of
105 the form [date]T[clock] (append T to -JX|x). At least one of
106 date and clock must be present; the T is always required. The
107 date string must be of the form [-]yyyy[-mm[-dd]] (Gregorian
108 calendar) or yyyy[-Www[-d]] (ISO week calendar), while the clock
109 string must be of the form hh:mm:ss[.xxx]. The use of delim‐
110 iters and their type and positions must be exactly as indicated
111 (however, input, output and plot formats are customizable; see
112 gmtdefaults).
113
115 No space between the option flag and the associated arguments.
116 -B Sets map boundary annotation and tickmark intervals; see the
119 psbasemap man page for all the details.
120 -E Sets the viewpoint's azimuth and elevation [180/90].
122 -H Input file(s) has Header record(s). Number of header records
124 can be changed by editing your .gmtdefaults4 file. If used, GMT
125 default is 1 header record. Use -Hi if only input data should
126 have header records [Default will write out header records if
127 the input data have them]. Blank lines and lines starting with #
128 are always skipped.
129 -K More PostScript code will be appended later [Default terminates
131 the plot system].
132 -M Multiple segment file. Segments are separated by a record whose
134 first character is <flag>. [Default is '>'].
135 -N Invert the sense of what is inside and outside, i.e., use the
137 outside of the polygons for clipping.
138 -O Selects Overlay plot mode [Default initializes a new plot sys‐
140 tem].
141 -P Selects Portrait plotting mode [Default is Landscape, see gmtde‐
143 faults to change this].
144 -U Draw Unix System time stamp on plot. By adding just/dx/dy/, the
146 user may specify the justification of the stamp and where the
147 stamp should fall on the page relative to lower left corner of
148 the plot. For example, BL/0/0 will align the lower left corner
149 of the time stamp with the lower left corner of the plot.
150 Optionally, append a label, or c (which will plot the command
151 string.). The GMT parameters UNIX_TIME, UNIX_TIME_POS, and
152 UNIX_TIME_FORMAT can affect the appearance; see the gmtdefaults
153 man page for details. The time string will be in the locale set
154 by the environment variable TZ (generally local time).
155 -V Selects verbose mode, which will send progress reports to stderr
157 [Default runs "silently"].
158 -X -Y Shift plot origin relative to the current origin by (x-shift,y-
160 shift) and optionally append the length unit (c, i, m, p). You
161 can prepend a to shift the origin back to the original position
162 after plotting, or prepend r [Default] to reset the current
163 origin to the new location. If -O is used then the default (x-
164 shift,y-shift) is (0,0), otherwise it is (r1i, r1i) or (r2.5c,
165 r2.5c). Alternatively, give c to align the center coordinate (x
166 or y) of the plot with the center of the page based on current
167 page size.
168 -Z For 3-D projections: Sets the z-level of the polygons [0].
170 -: Toggles between (longitude,latitude) and (latitude,longitude)
172 input and/or output. [Default is (longitude,latitude)]. Append
173 i to select input only or o to select output only. [Default
174 affects both].
175 -bi Selects binary input. Append s for single precision [Default is
177 d (double)]. Uppercase S or D will force byte-swapping.
178 Optionally, append ncol, the number of columns in your binary
179 input file if it exceeds the columns needed by the program. Or
180 append c if the input file is netCDF. Optionally, append
181 var1/var2/... to specify the variables to be read. [Default is
182 2 input columns].
183 -c Specifies the number of plot copies. [Default is 1].
185 -f Special formatting of input and/or output columns (time or geo‐
187 graphical data). Specify i or o to make this apply only to
188 input or output [Default applies to both]. Give one or more
189 columns (or column ranges) separated by commas. Append T (abso‐
190 lute calendar time), t (relative time in chosen TIME_UNIT since
191 TIME_EPOCH), x (longitude), y (latitude), or f (floating point)
192 to each column or column range item. Shorthand -f[i|o]g means
193 -f[i|o]0x,1y (geographic coordinates).
194
196 To make an overlay PostScript file that will set up a complex clip area
197 to which subsequent plotting will be confined, run:
198 psclip my_region.xy -R0/40/0/40 -Jm0.3i -O -K > clip_mask_on.ps
200 To deactivate the clipping in an existing plotfile, run:
202 psclip -C -O >> complex_plot.ps
204
206 psclip cannot handle polygons that contain the south or north pole.
207 For such polygons, you should split them into two and make each explic‐
208 itly contain the polar point. The two clip polygons will combine to
209 give the desired effect.
210
212 GMT(1), grdmask(1), psbasemap(1), psmask(1)
213GMT 4.3.1 15 May 2008 PSCLIP(1)