term% cat index.txt MAP(7) Miscellaneous Information Manual 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 display by any
plotting filter described in plot(1). A menu of projections is pro‐
duced in response to an unknown projection. For the meanings of params
pertinent to particular 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 miss‐
ing rank is taken to be 1. Features 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 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 pre‐
vious position of meridian rot. Project the desired map in the
standard form appropriate to the overlay, but presenting infor‐
mation 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 longitudes in the
tilted, rotated coordinate system. (It is wise to give an en‐
compassing -l option with -w. Otherwise for small windows com‐
puting 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. Miss‐
ing 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 plotting 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,
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 char‐
acter 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 de‐
fault 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 per‐
spective 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)
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 op‐
tions.
Segments that cross a map border are dropped.
bowell MAP(7)