2 <title>map(1) - Plan 9 from User Space</title>
3 <meta content="text/html; charset=utf-8" http-equiv=Content-Type>
6 <table border=0 cellpadding=0 cellspacing=0 width=100%>
9 <tr><td width=20><td><b>MAP(1)</b><td align=right><b>MAP(1)</b>
10 <tr><td width=20><td colspan=2>
12 <p><font size=+1><b>NAME </b></font><br>
14 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
16 map, mapdemo, mapd – draw maps on various projections<br>
19 <p><font size=+1><b>SYNOPSIS </b></font><br>
21 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
23 <tt><font size=+1>map</font></tt> <i>projection</i> [ <i>option ...</i> ]
24 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
26 <tt><font size=+1>mapdemo
27 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
31 <p><font size=+1><b>DESCRIPTION </b></font><br>
33 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
35 <i>Map</i> prepares on the standard output a map suitable for display
36 by any plotting filter described in <a href="../man1/plot.html"><i>plot</i>(1)</a>. A menu of projections
37 is produced in response to an unknown <i>projection</i>. <i>Mapdemo</i> is a
38 short course in mapping.
39 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
41 The default data for <i>map</i> are world shorelines. Option <tt><font size=+1>−f</font></tt> accesses
42 more detailed data classified by feature.<br>
43 <tt><font size=+1>−f</font></tt> [ <i>feature</i> ... ]<br>
45 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
47 Features are ranked 1 (default) to 4 from major to minor. Higher-numbered
48 ranks include all lower-numbered ones. Features are<br>
49 <tt><font size=+1>shore</font></tt>[<tt><font size=+1>1</font></tt>-<tt><font size=+1>4</font></tt>] seacoasts, lakes, and islands; option <tt><font size=+1>−f</font></tt> always shows
50 <tt><font size=+1>shore1<br>
51 ilake</font></tt>[<tt><font size=+1>1</font></tt>-<tt><font size=+1>2</font></tt>] intermittent lakes<br>
52 <tt><font size=+1>river</font></tt>[<tt><font size=+1>1</font></tt>-<tt><font size=+1>4</font></tt>] rivers<br>
53 <tt><font size=+1>iriver</font></tt>[<tt><font size=+1>1</font></tt>-<tt><font size=+1>3</font></tt>] intermittent rivers<br>
54 <tt><font size=+1>canal</font></tt>[<tt><font size=+1>1</font></tt>-<tt><font size=+1>3</font></tt>]<tt><font size=+1> 3</font></tt>=irrigation canals<br>
55 <tt><font size=+1>glacier<br>
56 iceshelf</font></tt>[<tt><font size=+1>12</font></tt>]<br>
57 <tt><font size=+1>reef<br>
58 saltpan</font></tt>[<tt><font size=+1>12</font></tt>]<br>
59 <tt><font size=+1>country</font></tt>[<tt><font size=+1>1</font></tt>-<tt><font size=+1>3</font></tt>]<tt><font size=+1> 2</font></tt>=disputed boundaries, <tt><font size=+1>3</font></tt>=indefinite boundaries<br>
60 <tt><font size=+1>state</font></tt> states and provinces (US and Canada only)<br>
62 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
66 In other options coordinates are in degrees, with north latitude
67 and west longitude counted as positive.<br>
68 <tt><font size=+1>−l</font></tt> <i>S N E W<br>
70 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
72 Set the southern and northern latitude and the eastern and western
73 longitude limits. Missing arguments are filled out from the list
74 –90, 90, –180, 180, or lesser limits suitable to the projection
78 <tt><font size=+1>−k</font></tt> <i>S N E W<br>
80 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
82 Set the scale as if for a map with limits <tt><font size=+1>−l</font></tt> <i>S N E W</i> . Do not
83 consider any <tt><font size=+1>−l</font></tt> or <tt><font size=+1>−w</font></tt> option in setting scale.<br>
86 <tt><font size=+1>−o</font></tt> <i>lat lon rot<br>
88 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
90 Orient the map in a nonstandard position. Imagine a transparent
91 gridded sphere around the globe. Turn the overlay about the North
92 Pole so that the Prime Meridian (longitude 0) of the overlay coincides
93 with meridian <i>lon</i> on the globe. Then tilt the North Pole of the
94 overlay along its Prime Meridian to latitude <i>lat
95 </i>on the globe. Finally again turn the overlay about its ‘North
96 Pole’ so that its Prime Meridian coincides with the previous position
97 of meridian <i>rot</i>. Project the map in the standard form appropriate
98 to the overlay, but presenting information from the underlying
99 globe. Missing arguments are filled out from the list
100 90, 0, 0. In the absence of <tt><font size=+1>−</font></tt>o<tt><font size=+1>,</font></tt> the orientation is 90, 0, <i>m</i>, where
101 <i>m</i> is the middle of the longitude range.<br>
104 <tt><font size=+1>−w</font></tt> <i>S N E W<br>
106 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
108 Window the map by the specified latitudes and longitudes in the
109 tilted, rotated coordinate system. Missing arguments are filled
110 out from the list –90, 90, –180, 180. (It is wise to give an encompassing
111 <tt><font size=+1>−l</font></tt> option with <tt><font size=+1>−w</font></tt>. Otherwise for small windows computing time
112 varies inversely with area!)
115 <tt><font size=+1>−d</font></tt> <i>n</i> For speed, plot only every <i>n</i>th point.<br>
116 <tt><font size=+1>−r</font></tt> Reverse left and right (good for star charts and inside-out
118 <tt><font size=+1>−v</font></tt> Verso. Switch to a normally suppressed sheet of the map, such
119 as the back side of the earth in orthographic projection.<br>
120 <tt><font size=+1>−s1<br>
121 −s2</font></tt> Superpose; outputs for a <tt><font size=+1>−s1</font></tt> map (no closing) and a <tt><font size=+1>−s2</font></tt> map
122 (no opening) may be concatenated.<br>
123 <tt><font size=+1>−g</font></tt> <i>dlat dlon res<br>
125 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
127 Grid spacings are <i>dlat</i>, <i>dlon</i>. Zero spacing means no grid. Missing
128 <i>dlat</i> is taken to be zero. Missing <i>dlon</i> is taken the same as <i>dlat</i>.
129 Grid lines are drawn to a resolution of <i>res</i> (2° or less by default).
130 In the absence of <tt><font size=+1>−</font></tt>g<tt><font size=+1>,</font></tt> grid spacing is 10°.<br>
133 <tt><font size=+1>−p</font></tt> <i>lat lon extent<br>
135 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
137 Position the point <i>lat, lon</i> at the center of the plotting area.
138 Scale the map so that the height (and width) of the nominal plotting
139 area is <i>extent</i> times the size of one degree of latitude at the
140 center. By default maps are scaled and positioned to fit within
141 the plotting area. An <i>extent</i> overrides option <tt><font size=+1>−k</font></tt>.
144 <tt><font size=+1>−c</font></tt> <i>x y rot<br>
146 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
148 After all other positioning and scaling operations have been performed,
149 rotate the image <i>rot</i> degrees counterclockwise about the center
150 and move the center to position <i>x</i>, <i>y</i>, where the nominal plotting
151 area is –1≤<i>x</i>≤1, –1≤<i>y</i>≤1. Missing arguments are taken to be 0. <tt><font size=+1>−x</font></tt> Allow
152 the map to extend outside the
153 nominal plotting area.<br>
156 <tt><font size=+1>−m</font></tt> [ <i>file</i> ... ]<br>
158 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
160 Use map data from named files. If no files are named, omit map
161 data. Names that do not exist as pathnames are looked up in a
162 standard directory, which contains, in addition to the data for
163 <tt><font size=+1>−f</font></tt>,<br>
165 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
167 <tt><font size=+1>world</font></tt> World Data Bank I (default)<br>
168 <tt><font size=+1>states</font></tt> US map from Census Bureau<br>
169 <tt><font size=+1>counties</font></tt> US map from Census Bureau<br>
170 The environment variables <tt><font size=+1>MAP</font></tt> and <tt><font size=+1>MAPDIR</font></tt> change the default map
171 and default directory.<br>
174 <tt><font size=+1>−b</font></tt> [<i>lat0 lon0 lat1 lon1</i>... ]<br>
176 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
178 Suppress the drawing of the normal boundary (defined by options
179 <tt><font size=+1>−l</font></tt> and <tt><font size=+1>−w</font></tt>). Coordinates, if present, define the vertices of a
180 polygon to which the map is clipped. If only two vertices are
181 given, they are taken to be the diagonal of a rectangle. To draw
182 the polygon, give its vertices as a <tt><font size=+1>−u</font></tt> track.
185 <tt><font size=+1>−t</font></tt> <i>file ...<br>
187 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
189 The <i>files</i> contain lists of points, given as latitude-longitude
190 pairs in degrees. If the first file is named <tt><font size=+1>−</font></tt>, the standard input
191 is taken instead. The points of each list are plotted as connected
192 ‘tracks’.<br>
193 Points in a track file may be followed by label strings. A label
194 breaks the track. A label may be prefixed by <tt><font size=+1>"</font></tt>, <tt><font size=+1>:</font></tt>, or <tt><font size=+1>!</font></tt> and is
195 terminated by a newline. An unprefixed string or a string prefixed
196 with <tt><font size=+1>"</font></tt> is displayed at the designated point. The first word of
197 a <tt><font size=+1>:</font></tt> or <tt><font size=+1>!</font></tt> string names a special symbol (see option <tt><font size=+1>−y</font></tt>).
198 An optional numerical second word is a scale factor for the size
199 of the symbol, 1 by default. A <tt><font size=+1>:</font></tt> symbol is aligned with its top
200 to the north; a <tt><font size=+1>!</font></tt> symbol is aligned vertically on the page.<br>
203 <tt><font size=+1>−u</font></tt> <i>file ...<br>
205 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
207 Same as <tt><font size=+1>−t</font></tt>, except the tracks are unbroken lines. (<tt><font size=+1>−t</font></tt> tracks appear
208 as dot-dashed lines if the plotting filter supports them.)<br>
211 <tt><font size=+1>−y</font></tt> <i>file<br>
213 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
215 The <i>file</i> contains <a href="../man7/plot.html"><i>plot</i>(7)</a>-style data for <tt><font size=+1>:</font></tt> or <tt><font size=+1>!</font></tt> labels in <tt><font size=+1>−t</font></tt> or
216 <tt><font size=+1>−u</font></tt> files. Each symbol is defined by a comment <tt><font size=+1>:</font></tt><i>name</i> then a sequence
217 of <tt><font size=+1>m</font></tt> and <tt><font size=+1>v</font></tt> commands. Coordinates (0,0) fall on the plotting point.
218 Default scaling is as if the nominal plotting range were <tt><font size=+1>ra −1
219 −1 1 1</font></tt>; <tt><font size=+1>ra</font></tt> commands in <i>file</i> change the
223 <p><font size=+1><b>Projections </b></font><br>
224 Equatorial projections centered on the Prime Meridian (longitude
225 0). Parallels are straight horizontal lines.
226 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
228 <tt><font size=+1>mercator</font></tt> equally spaced straight meridians, conformal, straight
230 <tt><font size=+1>sinusoidal</font></tt> equally spaced parallels, equal-area, same as <tt><font size=+1>bonne
232 <tt><font size=+1>cylequalarea</font></tt> <i>lat0</i> equally spaced straight meridians, equal-area,
233 true scale on <i>lat0<br>
234 </i><tt><font size=+1>cylindrical</font></tt> central projection on tangent cylinder<br>
235 <tt><font size=+1>rectangular</font></tt> <i>lat0</i> equally spaced parallels, equally spaced straight
236 meridians, true scale on <i>lat0<br>
237 </i><tt><font size=+1>gall</font></tt> <i>lat0</i> parallels spaced stereographically on prime meridian,
238 equally spaced straight meridians, true scale on <i>lat0<br>
239 </i><tt><font size=+1>mollweide</font></tt> (homalographic) equal-area, hemisphere is a circle<br>
241 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
244 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
246 <tt><font size=+1>gilbert()</font></tt> sphere conformally mapped on hemisphere and viewed orthographically<br>
251 <tt><font size=+1>gilbert</font></tt> globe mapped conformally on hemisphere, viewed orthographically
253 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
255 Azimuthal projections centered on the North Pole. Parallels are
256 concentric circles. Meridians are equally spaced radial lines.
258 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
260 <tt><font size=+1>azequidistant</font></tt> equally spaced parallels, true distances from pole<br>
261 <tt><font size=+1>azequalarea</font></tt> equal-area<br>
262 <tt><font size=+1>gnomonic</font></tt> central projection on tangent plane, straight great circles<br>
263 <tt><font size=+1>perspective</font></tt> <i>dist</i> viewed along earth’s axis <i>dist</i> earth radii from
265 <tt><font size=+1>orthographic</font></tt> viewed from infinity<br>
266 <tt><font size=+1>stereographic</font></tt> conformal, projected from opposite pole<br>
267 <tt><font size=+1>laue</font></tt><i>radius</i> = tan(2×<i>colatitude</i>), used in X-ray crystallography<br>
268 <tt><font size=+1>fisheye</font></tt> <i>n</i> stereographic seen from just inside medium with refractive
270 </i><tt><font size=+1>newyorker</font></tt> <i>rradius</i> = log(<i>colatitude</i>/<i>r</i>): <i>New Yorker</i> map from viewing
271 pedestal of radius <i>r</i> degrees
272 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
274 Polar conic projections symmetric about the Prime Meridian. Parallels
275 are segments of concentric circles. Except in the Bonne projection,
276 meridians are equally spaced radial lines orthogonal to the parallels.
278 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
280 <tt><font size=+1>conic</font></tt> <i>lat0</i> central projection on cone tangent at <i>lat0<br>
281 </i><tt><font size=+1>simpleconic</font></tt> <i>lat0 lat1<br>
283 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
286 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
288 equally spaced parallels, true scale on <i>lat0</i> and <i>lat1<br>
293 <tt><font size=+1>lambert</font></tt> <i>lat0 lat1</i> conformal, true scale on <i>lat0</i> and <i>lat1<br>
294 </i><tt><font size=+1>albers</font></tt> <i>lat0 lat1</i> equal-area, true scale on <i>lat0</i> and <i>lat1<br>
295 </i><tt><font size=+1>bonne</font></tt> <i>lat0</i> equally spaced parallels, equal-area, parallel <i>lat0</i>
296 developed from tangent cone
297 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
299 Projections with bilateral symmetry about the Prime Meridian and
301 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
303 <tt><font size=+1>polyconic</font></tt> parallels developed from tangent cones, equally spaced
304 along Prime Meridian<br>
305 <tt><font size=+1>aitoff</font></tt> equal-area projection of globe onto 2-to-1 ellipse, based
306 on <i>azequalarea<br>
307 </i><tt><font size=+1>lagrange</font></tt> conformal, maps whole sphere into a circle<br>
308 <tt><font size=+1>bicentric</font></tt> <i>lon0</i> points plotted at true azimuth from two centers
309 on the equator at longitudes <i>±lon0</i>, great circles are straight
310 lines (a stretched <i>gnomonic</i> )<br>
311 <tt><font size=+1>elliptic</font></tt> <i>lon0</i> points plotted at true distance from two centers
312 on the equator at longitudes <i>±lon0<br>
313 </i><tt><font size=+1>globular</font></tt> hemisphere is circle, circular arc meridians equally spaced
314 on equator, circular arc parallels equally spaced on 0- and 90-degree
316 <tt><font size=+1>vandergrinten</font></tt> sphere is circle, meridians as in <i>globular</i>, circular
317 arc parallels resemble <i>mercator
318 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
320 Doubly periodic conformal projections.
321 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
323 <tt><font size=+1>guyou</font></tt> W and E hemispheres are square<br>
324 <tt><font size=+1>square</font></tt> world is square with Poles at diagonally opposite corners<br>
325 <tt><font size=+1>tetra</font></tt> map on tetrahedron with edge tangent to Prime Meridian at
326 S Pole, unfolded into equilateral triangle<br>
327 <tt><font size=+1>hex</font></tt> world is hexagon centered on N Pole, N and S hemispheres are
328 equilateral triangles
329 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
331 Miscellaneous projections.
332 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
334 <tt><font size=+1>harrison</font></tt> <i>dist angle</i>oblique perspective from above the North Pole,
335 <i>dist</i> earth radii from center of earth, looking along the Date
336 Line <i>angle</i> degrees off vertical<br>
337 <tt><font size=+1>trapezoidal</font></tt> <i>lat0 lat1<br>
339 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
342 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
344 equally spaced parallels, straight meridians equally spaced along
345 parallels, true scale at <i>lat0</i> and <i>lat1</i> on Prime Meridian<br>
346 <tt><font size=+1>lune(lat,angle)</font></tt> conformal, polar cap above latitude <i>lat</i> maps to
347 convex lune with given <i>angle</i> at 90°E and 90°W
348 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
354 Retroazimuthal projections. At every point the angle between vertical
355 and a straight line to ‘Mecca’, latitude <i>lat0</i> on the prime meridian,
356 is the true bearing of Mecca.
357 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
359 <tt><font size=+1>mecca</font></tt> <i>lat0</i> equally spaced vertical meridians<br>
360 <tt><font size=+1>homing</font></tt> <i>lat0</i> distances to Mecca are true
361 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
363 Maps based on the spheroid. Of geodetic quality, these projections
364 do not make sense for tilted orientations. For descriptions, see
365 corresponding maps above.
366 <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
368 <tt><font size=+1>sp_mercator<br>
369 sp_albers</font></tt> <i>lat0 lat1<br>
372 <p><font size=+1><b>EXAMPLES </b></font><br>
374 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
376 <tt><font size=+1>map perspective 1.025 −o 40.75 74<br>
378 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
380 A view looking down on New York from 100 miles (0.025 of the 4000-mile
381 earth radius) up. The job can be done faster by limiting the map
382 so as not to ‘plot’ the invisible part of the world: <tt><font size=+1>map perspective
383 1.025 −o 40.75 74 −l 20 60 30 100</font></tt>. A circular border can be forced
385 <tt><font size=+1>−w 77.33</font></tt>. (Latitude 77.33° falls just inside a polar cap of opening
386 angle arccos(1/1.025) = 12.6804°.)<br>
389 <tt><font size=+1>map mercator −o 49.25 −106 180<br>
391 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
393 An ‘equatorial’ map of the earth centered on New York. The pole
394 of the map is placed 90° away (40.75+49.25=90) on the other side
395 of the earth. A 180° twist around the pole of the map arranges
396 that the ‘Prime Meridian’ of the map runs from the pole of the
397 map over the North Pole to New York instead of
398 down the back side of the earth. The same effect can be had from
399 <tt><font size=+1> map mercator −o 130.75 74<br>
402 <tt><font size=+1>map albers 28 45 −l 20 50 60 130 −m states<br>
404 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
406 A customary curved-latitude map of the United States.<br>
409 <tt><font size=+1>map harrison 2 30 −l −90 90 120 240 −o 90 0 0<br>
411 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
413 A fan view covering 60° on either side of the Date Line, as seen
414 from one earth radius above the North Pole gazing at the earth’s
415 limb, which is 30° off vertical. The <tt><font size=+1>−o</font></tt> option overrides the default
416 <tt><font size=+1>−o 90 0 180</font></tt>, which would rotate the scene to behind the observer.<br>
421 <p><font size=+1><b>FILES </b></font><br>
423 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
425 <tt><font size=+1>/lib/map/[1−4]??</font></tt> World Data Bank II, for <tt><font size=+1>−f<br>
426 /lib/map/*</font></tt> maps for <tt><font size=+1>−m<br>
427 /lib/map/*.x</font></tt> map indexes<br>
428 <tt><font size=+1>mapd</font></tt> Map driver program<br>
431 <p><font size=+1><b>SOURCE </b></font><br>
433 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
435 <tt><font size=+1>/usr/local/plan9/src/cmd/map<br>
438 <p><font size=+1><b>SEE ALSO </b></font><br>
440 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
442 <a href="../man7/map.html"><i>map</i>(7)</a>, <a href="../man1/plot.html"><i>plot</i>(1)</a><br>
445 <p><font size=+1><b>DIAGNOSTICS </b></font><br>
447 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
449 ‘Map seems to be empty’--a coarse survey found zero extent within
450 the <tt><font size=+1>−l</font></tt> and <tt><font size=+1>−w</font></tt> bounds; for maps of limited extent the grid resolution,
451 <i>res</i>, or the limits may have to be refined.<br>
454 <p><font size=+1><b>BUGS </b></font><br>
456 <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
458 Windows (option <tt><font size=+1>−w</font></tt>) cannot cross the Date Line. No borders appear
459 along edges arising from visibility limits. Segments that cross
460 a border are dropped, not clipped. Excessively large scale or
461 <tt><font size=+1>−d</font></tt> setting may cause long line segments to be dropped. <i>Map</i> tries
462 to draw grid lines dotted and <tt><font size=+1>−t</font></tt> tracks dot-dashed. As
463 very few plotting filters properly support curved textured lines,
464 these lines are likely to appear solid. The west-longitude-positive
465 convention betrays Yankee chauvinism. <i>Gilbert</i> should be a map
466 from sphere to sphere, independent of the mapping from sphere
475 <table border=0 cellpadding=0 cellspacing=0 width=100%>
476 <tr height=15><td width=10><td><td width=10>
479 <a href="../../"><img src="../../dist/spaceglenda100.png" alt="Space Glenda" border=1></a>
