3 map, mapdemo, mapd \- draw maps on various projections
15 prepares on the standard output a
16 map suitable for display by any
17 plotting filter described in
19 A menu of projections is produced in response to an unknown
22 is a short course in mapping.
29 accesses more detailed data
30 classified by feature.
32 .BR -f " [ \fIfeature\fR ... ]"
33 Features are ranked 1 (default) to 4 from major to minor.
34 Higher-numbered ranks include all lower-numbered ones.
40 seacoasts, lakes, and islands; option
73 states and provinces (US and Canada only)
78 coordinates are in degrees, with north latitude
79 and west longitude counted as positive.
82 Set the southern and northern latitude
83 and the eastern and western longitude limits.
84 Missing arguments are filled out from the list
86 or lesser limits suitable to the
90 Set the scale as if for a map with limits
97 option in setting scale.
100 Orient the map in a nonstandard position.
101 Imagine a transparent gridded sphere around the globe.
102 Turn the overlay about the North Pole
103 so that the Prime Meridian (longitude 0)
104 of the overlay coincides with meridian
107 Then tilt the North Pole of the
108 overlay along its Prime Meridian to latitude
111 Finally again turn the
112 overlay about its `North Pole' so
113 that its Prime Meridian coincides with the previous position
117 the standard form appropriate to the overlay, but presenting
118 information from the underlying globe.
119 Missing arguments are filled out from the list
123 the orientation is 90, 0,
127 is the middle of the longitude range.
130 Window the map by the specified latitudes
131 and longitudes in the tilted, rotated coordinate system.
132 Missing arguments are filled out from the list \-90, 90, \-180, 180.
133 (It is wise to give an encompassing
137 Otherwise for small windows computing time
138 varies inversely with area!)
141 For speed, plot only every
146 Reverse left and right
147 (good for star charts and inside-out views).
152 Switch to a normally suppressed sheet of the map, such as the
153 back side of the earth in orthographic projection.
160 Superpose; outputs for a
162 map (no closing) and a
164 map (no opening) may be concatenated.
166 .BI -g " dlat dlon res"
170 Zero spacing means no grid.
178 Grid lines are drawn to a resolution of
180 (2° or less by default).
185 .BI -p " lat lon extent"
188 at the center of the plotting area.
189 Scale the map so that the height (and width) of the
190 nominal plotting area is
192 times the size of one degree of latitude
194 By default maps are scaled and positioned
195 to fit within the plotting area.
202 After all other positioning and scaling operations
203 have been performed, rotate the image
205 degrees counterclockwise about the center
206 and move the center to position
209 where the nominal plotting area is
212 Missing arguments are taken to be 0.
214 Allow the map to extend outside the nominal plotting area.
216 .BR -m " [ \fIfile\fP ... ]"
218 map data from named files.
219 If no files are named, omit map data.
220 Names that do not exist as pathnames are looked up in
221 a standard directory, which contains, in addition to the
229 World Data Bank I (default)
232 US map from Census Bureau
235 US map from Census Bureau
239 The environment variables
244 map and default directory.
246 .BI -b " \fR[\fPlat0 lon0 lat1 lon1\fR... ]"
247 Suppress the drawing of the normal boundary
252 Coordinates, if present, define the vertices of a
253 polygon to which the map is clipped.
254 If only two vertices are given, they are taken to be the
255 diagonal of a rectangle.
256 To draw the polygon, give its vertices as a
263 contain lists of points,
264 given as latitude-longitude pairs in degrees.
265 If the first file is named
267 the standard input is taken instead.
268 The points of each list are plotted as connected `tracks'.
270 Points in a track file may be followed by label strings.
271 A label breaks the track.
272 A label may be prefixed by
277 and is terminated by a newline.
278 An unprefixed string or a string prefixed with
281 is displayed at the designated point.
286 string names a special symbol (see option
288 An optional numerical second word is a scale factor
289 for the size of the symbol, 1 by default.
292 symbol is aligned with its top to the north; a
294 symbol is aligned vertically on the page.
299 except the tracks are
302 tracks appear as dot-dashed lines if the plotting filter supports them.)
318 Each symbol is defined by a comment
325 Coordinates (0,0) fall on the plotting point.
326 Default scaling is as if the nominal plotting range were
333 Equatorial projections centered on the Prime Meridian
335 Parallels are straight horizontal lines.
340 equally spaced straight meridians, conformal,
341 straight compass courses
344 equally spaced parallels,
348 .BI cylequalarea " lat0"
349 equally spaced straight meridians, equal-area,
354 central projection on tangent cylinder
356 .BI rectangular " lat0"
357 equally spaced parallels, equally spaced straight meridians, true scale on
361 parallels spaced stereographically on prime meridian, equally spaced straight
362 meridians, true scale on
366 (homalographic) equal-area, hemisphere is a circle
369 sphere conformally mapped on hemisphere and viewed orthographically
372 globe mapped conformally on hemisphere, viewed orthographically
375 Azimuthal projections centered on the North Pole.
376 Parallels are concentric circles.
377 Meridians are equally spaced radial lines.
382 equally spaced parallels,
383 true distances from pole
389 central projection on tangent plane,
390 straight great circles
392 .BI perspective " dist"
393 viewed along earth's axis
395 earth radii from center of earth
401 conformal, projected from opposite pole
404 .IR radius " = tan(2\(mu" colatitude ),
405 used in X-ray crystallography
408 stereographic seen from just inside medium with refractive index
412 .IR radius " = log(" colatitude / r ):
414 map from viewing pedestal of radius
419 Polar conic projections symmetric about the Prime Meridian.
420 Parallels are segments of concentric circles.
421 Except in the Bonne projection,
422 meridians are equally spaced radial
423 lines orthogonal to the parallels.
428 central projection on cone tangent at
431 .BI simpleconic " lat0 lat1"
432 equally spaced parallels, true scale on
437 .BI lambert " lat0 lat1"
438 conformal, true scale on
443 .BI albers " lat0 lat1"
444 equal-area, true scale on
450 equally spaced parallels, equal-area,
453 developed from tangent cone
456 Projections with bilateral symmetry about
463 parallels developed from tangent cones,
464 equally spaced along Prime Meridian
467 equal-area projection of globe onto 2-to-1
472 conformal, maps whole sphere into a circle
474 .BI bicentric " lon0"
475 points plotted at true azimuth from two
476 centers on the equator at longitudes
478 great circles are straight lines
484 points plotted at true distance from
485 two centers on the equator at longitudes
489 hemisphere is circle,
490 circular arc meridians equally spaced on equator,
491 circular arc parallels equally spaced on 0- and 90-degree meridians
497 circular arc parallels resemble
501 Doubly periodic conformal projections.
505 W and E hemispheres are square
509 world is square with Poles
510 at diagonally opposite corners
513 map on tetrahedron with edge
514 tangent to Prime Meridian at S Pole,
515 unfolded into equilateral triangle
518 world is hexagon centered
519 on N Pole, N and S hemispheres are equilateral
523 Miscellaneous projections.
527 .BI harrison " dist angle"
528 oblique perspective from above the North Pole,
530 earth radii from center of earth, looking
535 .BI trapezoidal " lat0 lat1"
536 equally spaced parallels,
537 straight meridians equally spaced along parallels,
546 conformal, polar cap above latitude
548 maps to convex lune with given
550 at 90\(deE and 90\(deW
552 Retroazimuthal projections.
553 At every point the angle between vertical and a straight line to
556 on the prime meridian,
557 is the true bearing of Mecca.
562 equally spaced vertical meridians
565 distances to Mecca are true
568 Maps based on the spheroid.
569 Of geodetic quality, these projections do not make sense
570 for tilted orientations.
571 For descriptions, see corresponding maps above.
577 .BI sp_albers " lat0 lat1"
581 map perspective 1.025 -o 40.75 74
582 A view looking down on New York from 100 miles
583 (0.025 of the 4000-mile earth radius) up.
584 The job can be done faster by limiting the map so as not to `plot'
585 the invisible part of the world:
586 .LR "map perspective 1.025 -o 40.75 74 -l 20 60 30 100".
587 A circular border can be forced by adding option
589 (Latitude 77.33° falls just inside a polar cap of
590 opening angle arccos(1/1.025) = 12.6804°.)
593 map mercator -o 49.25 -106 180
594 An `equatorial' map of the earth
595 centered on New York.
596 The pole of the map is placed 90\(de away (40.75+49.25=90)
598 other side of the earth.
599 A 180° twist around the pole of the map arranges that the
600 `Prime Meridian' of the map runs from the pole of the
601 map over the North Pole to New York
602 instead of down the back side of the earth.
603 The same effect can be had from
605 map mercator -o 130.75 74
608 map albers 28 45 -l 20 50 60 130 -m states
609 A customary curved-latitude map of the United States.
612 map harrison 2 30 -l -90 90 120 240 -o 90 0 0
613 A fan view covering 60° on either
614 side of the Date Line, as seen from one earth radius
615 above the North Pole gazing at the
616 earth's limb, which is 30° off vertical.
619 option overrides the default
622 the scene to behind the observer.
627 World Data Bank II, for
645 `Map seems to be empty'\(ema coarse survey found
646 zero extent within the
650 bounds; for maps of limited extent
653 or the limits may have to be refined.
657 cannot cross the Date Line.
658 No borders appear along edges arising from
660 Segments that cross a border are dropped, not clipped.
661 Excessively large scale or
663 setting may cause long line segments to be dropped.
665 tries to draw grid lines dotted and
668 As very few plotting filters properly support
669 curved textured lines, these lines are likely to
671 The west-longitude-positive convention
672 betrays Yankee chauvinism.
674 should be a map from sphere to sphere, independent of
675 the mapping from sphere to plane.
