coast [ parameter=value ... ] [ outputfile ]
Parameters are: master_file, reduce_factor, coast_file, var_name, line_color.
coast generates a TeraScan metafile dataset that contains the world coastline, rivers, U.S. state boundaries, and international boundaries for a user-specified region of the world. This metafile is based on a user-specified master dataset, and can be overlayed on top of any displayed image with the same earth transform as the master dataset.
Coastline data is generally extracted from either the Digital Chart of the world (DCW) or the Central Intelligence Agency (CIA) World Database II (WDB2). Resolution of the WDB2 database is allegedly one kilometer. However, this estimate is very optimistic for the remote areas of the world. Resolution of the DCW database is considerably better. The following coast files are available in the directory $REFDATA/coast, where $REFDATA is the TeraScan reference data directory:
Continents, major islands, and lakes
Major rivers
International boundaries
National boundaries, such as states
Subsampled combination of wdb2.cil, wdb2.bdy, and wdb2.states for drawing large-area maps.
Coastline, and islands with extents > 20 kilometers
Islands with extents < 20 kilometers
Lakes and two-sided rivers with extents > 20 kilometers
Lakes and two-sided rivers with extents < 20 kilometers
Rivers and streams
International boundaries
National boundaries, such as states
Subsampled combination of dcw.coast, dcw.political, and dcw.states for drawing large area maps.
Users can also specify their own coastline files. These files must either be TeraScan datasets with parallel latitude/longitude variables or binary files in the same format as the WDB2 or DCW files. (See coastfile.) In the case of TeraScan datasets, bad (missing) latitude/longitude values are interpreted as breaks in the coastline.
If a file's name is not fully qualified, the file is assumed to exist: (1) relative to the current directory, or (2) relative to the directory $REFDATA/coast.
This is the name of the master dataset used to specify the region for which a coast will be produced. See master for information on generating master datasets.
Valid responses are any TeraScan dataset that contains an earth transform. The default is Master.
This is the reduction factor used to reduce the resolution of the database and compress the size of the resulting output metafile.
The valid range is [1, 20]. The default is 1.
These are the names of files used to generate the coastline, rivers, and international and state boundaries. The default is wdb2.cil.
OPTIONAL. This is the name of the output variable that contains the graphics data. This name is unimportant unless the output variable will be copied to another dataset that already contains a variable with the name coastline. In this case var_name can be changed to avoid a name conflict.
Valid responses are any string up to 12 characters long. The default is coastline.
OPTIONAL. This is the color index for the metafile data. This index allows different portions of a metafile to have a unique color. It is normally used in special applications that involve combining multiple metafile datasets.
The valid range is [0, 255]. The default is 1.
Generate the continental coastline and international boundaries for North and Central America.
[1] % master output file : char(75) ? [Master] BIG_MASTER projection : char(13) ? rect center_lat : char(15) ? 30 30 N center_lon : char(15) ? 91 W num_lines : int ? 512 num_samples : int ? 512 pixel_width : real ? [1.1132] 16 pixel_height : real ? [1.1132] 16 rotate_angle : real ? [0] [2] % coast output file : char(75) ? [Coast] BIG_COAST master_file : char(75) ? [Master] BIG_MASTER reduce_factor : int ? [1] coast_file : char(75) ? [wdb2.cil] wdb2.cil wdb2.bdy
refdata/coast/wdb2.cil, refdata/coast/wdb2.riv, refdata/coast/wdb2.bdy, refdata/coast/wdb2.states, refdata/coast/wdb2.thin, refdata/coast/dcw.coast, refdata/coast/dcw.coast_20, refdata/coast/dcw.inland, refdata/coast/dcw.inland_20, refdata/coast/dcw.streams, refdata/coast/dcw.political, refdata/coast/dcw.states, refdata/coast/dcw.thin