MAP(7) MAP(7)
NAME
map - draw maps on various projections
SYNOPSIS
map projection [ param ... ] [ option ... ]
DESCRIPTION
Map prepares on the standard output a map suitable for dis-
play by any plotting filter described in plot(1). A menu of
projections is produced in response to an unknown
projection. For the meanings of params pertinent to particu-
lar projections see proj(3).
The default data for map are world shorelines. Option -f
accesses the higher-resolution World Data Bank II.
-f [ feature ... ]
Features are ranked 1 (default) to 4 from major to
minor. Higher-numbered ranks include all lower-
numbered ones. Features are
shore[1-4] seacoasts, lakes, and islands; in the
absence of -m, option -f automatically
includes shore1
ilake[1-2] intermittent lakes
river[1-4] rivers
iriver[1-3] intermittent rivers
canal[1-3] 3=irrigation canals
glacier
iceshelf[12]
reef
saltpan[12]
country[1-3] 2=disputed boundaries, 3=indefinite
boundaries
state states and provinces (US and Canada only)
In other options coordinates are in degrees, with north lat-
itude and west longitude counted as positive.
-l S N E W
Set the southern and northern latitude and the eastern
and western longitude limits. Missing arguments are
filled out from the list -90, 90, -180, 180.
-k S N E W
Set the scale as if for a map with limits -l S N E W
and no -w option.
-o lat lon rot
Orient the map in a nonstandard position. Imagine a
MAP(7) MAP(7)
transparent gridded sphere around the globe. Turn the
overlay about the North Pole so that the Prime Meridian
(longitude 0) of the overlay coincides with meridian
lon on the globe. Then tilt the North Pole of the
overlay along its Prime Meridian to latitude lat on the
globe. Finally again turn the overlay about its `North
Pole' so that its Prime Meridian coincides with the
previous position of meridian rot. Project the map in
the standard form appropriate to the overlay, but pre-
senting information from the underlying globe. Missing
arguments are filled out from the list 90, 0, 0. In
the absence of -o, the orientation is 90, 0, m, where m
is the middle of the longitude range.
-w S N E W
Window the map by the specified latitudes and longi-
tudes in the tilted, rotated coordinate system. Miss-
ing arguments are filled out from the list -90, 90,
-180, 180. (It is wise to give an encompassing -l
option with -w. Otherwise for small windows computing
time varies inversely with area!)
-d n For speed, plot only every nth point.
-r Reverse left and right (good for star charts and
inside-out views).
-s1
-s2 Superpose. Outputs for a -s1 map (no closing) and a
-s2 map (no opening) may be concatenated.
-g dlat dlon res
Grid spacings are dlat, dlon. Zero spacing means no
grid. Missing dlat is taken to be zero. Missing dlon
is taken the same as dlat. Grid lines are drawn to a
resolution of res (2° or less by default). In the
absence of -g, grid spacing is 10°.
-p lat lon extent
Position the point lat, lon at the center of a square
plotting area. Scale the map so that a side of the
square is extent times the size of one degree of lati-
tude at the center. By default maps are scaled and
positioned to fit within the plotting area. An extent
overrides option -k.
-c x y rot
After all other positioning and scaling operations,
rotate the image rot degrees counterclockwise about the
center and move the center to position x, y, of the
plotting area, whose nominal extent is -1≦x≦1, -1≦y≦1.
The map is clipped to this area. Missing arguments are
taken to be 0.
MAP(7) MAP(7)
-m [ file ... ]
Use map data from named files. If no files are named,
omit map data. Files that cannot be found directly are
looked up a standard directory, which contains, in
addition to the data for -f,
world World Data Bank I from CIA (default)
states US map from Census Bureau
counties US map from Census Bureau
The environment variables MAP and MAPDIR change the
default map and default directory.
-b [ lat1 lon1 lat2 lon2 ... ]
Suppress the drawing of the normal boundary (defined by
options -l and -w). Coordinates, if present, define
the vertices of a polygon to which the map is clipped.
If only two vertices are given, they are taken to be
the diagonal of a rectangle. To draw the polygon, give
its vertices as a -u track.
-t file ...
The arguments name ASCII files that contain lists of
points, given as latitude-longitude pairs in degrees.
If the first file is named `-', the standard input is
taken instead. The points of each list are plotted as
connected `tracks'.
Points in a track file may be followed by label
strings. A label breaks the track. A label may be
prefixed by ", `:', or `!' and is terminated by a new-
line. An unprefixed string or a string prefixed with "
is displayed at the designated point. The first word
of a `:' or `!' string names a special symbol (see
option -y). An optional numerical second word is a
scale factor for the size of the symbol, 1 by default.
A `:' symbol is aligned with its top to the north; a
`!' symbol is aligned vertically on the page.
-u file ...
Same as -t, except the tracks are unbroken lines. (-t
tracks are dot-dash lines.)
-y file
The file contains plot(5)-style data for `:' or `!'
labels in -t or -u files. Each symbol is defined by a
comment :name then a sequence of `m' and `v' commands.
Coordinates (0,0) fall on the plotting point. Default
scaling is as if the nominal plotting range were `ra -1
-1 1 1'; `ra' commands in file change the scaling.
EXAMPLES
MAP(7) MAP(7)
map perspective 1.025 -o 40.75 74
A view looking down on New York from 100 miles (0.025
of the 4000-mile earth radius). The job can be done
faster by limiting the map so as not to `plot' the
invisible part of the world: `map perspective 1.025 -o
40.75 74 -l 20 60 30 100'. A circular border can be
forced by adding option `-w 77.33'. (Latitude 77.33°
falls just inside a polar cap of opening angle arc-
cos(1/1.025) = 12.6804°.)
map mercator -o 49.25 -106 180
A map whose `equator' is a great circle pasing east-
west through New York. The pole of the map is placed
90° away (40.75+49.25=90) on the other side of the
earth. A 180° twist around the pole of the map
arranges that the Prime Meridian of the map runs from
the pole of the map over the North Pole to New York
instead of down the back side of the earth. The same
effect can be had from map mercator -o 130.75 74
map albers 28 45 -l 20 50 60 130 -m states
A customary curved-latitude map of the United States.
map albers 28 45 -l 20 50 60 130 -y yfile -t tfile
An example of tracks, labels, and symbols. Arrows at
New York and Miami are 8% and 12% as long as the map is
wide. The contents of `yfile' and `tfile' are
ra -50 -50 50 50 25.77 80.20 :arrow 12
:arrow 25.77 80.20 Miami
m -1 0 25.77 80.20
v 0 0 35.00 74.02
v -.6 .3 40.67 74.02 !arrow 8
m -.6 -.3 40.67 74.02 " New York
v 0 0 34.05 118.25 Los Angeles
map harrison 2 30 -l -90 90 120 240 -o 90 0 0
A fan view covering 60° on either
side of the Date Line, as seen from one earth radius
above the North Pole gazing at the
earth's limb, which is 30° off vertical.
Option
-o
overrides the default
-o 90 0 180,
which would rotate
the scene to behind the observer.
FILES
All files in directory $MAPDIR
World Data Bank II for option
-f
MAP(7) MAP(7)
world,states,counties
default and other maps for option -m
map indexes
the program proper
SEE ALSO
map(5), proj(3), plot(1)
DIAGNOSTICS
`Map seems to be empty'-a coarse survey found zero extent
within the -l and -w bounds; for maps of limited extent the
grid resolution, res, or the limits may have to be refined.
BUGS
The syntax of range specifications in -y files differs from
that in options.
Windows (option -w) cannot cross the Date Line.
No borders appear along edges arising from visibility lim-
its.
Segments that cross a border are dropped, not clipped.
Certain very long line segments are dropped on the assump-
tion that they were intended to go the other way around the
world.
Automatic scaling may miss the extreme points of peculiarly
shaped maps; use option -p to recover.
Although map draws grid lines dotted and -t tracks dot-
dashed, many plotting filters cannot cope and make them
solid.