MAP(7) (bowell) 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 map(3).
The default data for map are world shorelines. Option -f
accesses more detailed data classified by feature.
-f [ feature ] ...
Known features are ranked 1 to 4 from major to minor,
with a higher-numbered rank including all lower-
numbered ones. A missing rank is taken to be 1. Fea-
tures are
shore[1-4] seacoasts, lakes, and islands; option -f always shows shore1
ilake[1-2] intermittent lakes
river[1-4] rivers
iriver[1-3] intermittent rivers
canal[1-3] (canal3 = irrigation canals)
glacier
iceshelf[12]
reef
saltpan[12]
country[123] (country[23] = disputed and indefinite boundaries)
state states and provinces (US and Canada only)
In the following list of other options all coordinates are
in degrees, with north latitude and west longitude counted
as positive.
-l S N E W
the southern and northern latitude and the eastern and
western longitude limits of the desired map. Missing
arguments are filled out from the list -90, 90, -180,
180, or lesser limits suitable to the projection in
question.
-o lat lon rot
Orient the map in a nonstandard position. Imagine a
transparent gridded sphere around the globe. First
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
MAP(7) (bowell) MAP(7)
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
desired map in the standard form appropriate to the
overlay, but presenting information from the underlying
globe. Missing arguments are filled out from the list
90, 0, 0. Default 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. (It is
wise to give an encompassing -l option with -w. Other-
wise for small windows computing time varies inversely
with area!)
-d n Alter the density of points by plotting only every nth
one.
-r Reverse left and right side of map, for star charts and
inside-out views.
-s Save the screen, don't erase before drawing.
-g dlat dlon res
Grid spacings are dlat, dlon (10 degrees by default).
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 degrees by
default).
-p lat lon extent
Position the point lat, lon at the center of the plot-
ting area, and scale so that the height (and width) of
the nominal plotting area is extent times the size of
one degree of latitude at the center. For example, a
standard schoolroom-wall Mercator map comes out as if
positioned and scaled with -p 0 0 360.
-c x y
After all other positioning and scaling operations have
been performed, move the center of the map to position
x, y, where the nominal plotting area is -1≦x≦1,
-1≦y≦1.
-m [ file ] ...
Use map data from named files instead of the defaults.
If no files are named, plot grid only. Names not the
pathname of real files are looked up in a standard
directory, which contains, in addition to the data for
-f,
MAP(7) (bowell) MAP(7)
world World Data Bank I from CIA (the default map)
states US map from Census Bureau
counties US map from Census Bureau
-b Suppress border around map.
-t [ file ] ...
The following 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', i.e. dot-dashed lines
superimposed on the map. A nonnumeric field optionally
preceded by `"' ends a track. The field together with
everything up to the next newline is placed as a label
at the last point of the track, positioned so that a
leading character such as `+' or `X' will fall on the
point.
-u [ file ] ...
Same as -t, except the tracks are unbroken lines.
The environment variables MAP and MAPDIR change the default
map and default directory.
EXAMPLES
A `polar' map centered on New York (actually a low-orbit
view): map perspective 1.025 -o 40.75 74. 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.
An `equatorial' map of the earth centered on New York: map
mercator -o 49.25 -106 180. The pole of the map is placed
90 degrees away on the other side of the earth. A 180-
degree 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.
A customary curved-latitude map of the United States: map
albers 28 45 -l 20 50 60 130.
FILES
/n/bowell/usr1/maps default directory, contains following
files
101,102,...,403 World Data Bank II
world World Data Bank I
states
counties
SEE ALSO
map(5), map(3), plot(1)
MAP(7) (bowell) MAP(7)
DIAGNOSTICS
`map seems to be empty'-the intersection of the limits and
the window seems to be null; for very local maps, the grid
resolution res may have to be refined.
BUGS
Border lines appear only along boundaries that arise from -l
and -w options.
Segments that cross a map border are dropped.