NAME

       d.geodesic  - Displays a geodesic line, tracing the shortest distance between two geographic points along
       a great circle, in a longitude/latitude data set.

KEYWORDS

       display, distance, great circle, shortest path

SYNOPSIS

       d.geodesic
       d.geodesic --help
       d.geodesic  coordinates=lon1,lat1,lon2,lat2    [line_color=name]     [text_color=name]     [units=string]
       [--help]  [--verbose]  [--quiet]  [--ui]

   Flags:
       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       coordinates=lon1,lat1,lon2,lat2 [required]
           Starting and ending coordinates

       line_color=name
           Line color
           Either a standard color name or R:G:B triplet
           Default: black

       text_color=name
           Text color
           Either a standard color name or R:G:B triplet

       units=string
           Units
           Units
           Options: meters, kilometers, feet, miles
           Default: meters

DESCRIPTION

       d.geodesic  displays  a  geodesic  line  in the active frame on the user’s graphics monitor. This is also
       known as the great circle line and traces the shortest distance between two user-specified points on  the
       curved  surface of a longitude/latitude data set. The two coordinate locations named must fall within the
       boundaries of the user’s current geographic region.

OPTIONS

       By default black line color and red text color will be used.

       By indicating the starting and ending coordinates of the geodesic, the line and its length (by default in
       meters)  are  displayed  to  the  graphical  output.  If  the text color is set to none, the great circle
       distance is not displayed.

EXAMPLE

       A geodesic line if shown over the political map of the world (demolocation dataset):
       g.region vector=country_boundaries -p
       d.mon wx0
       d.vect country_boundaries type=area
       # show additionally a 20 degree grid
       d.grid 20
       d.geodesic coordinates=55:58W,33:18S,26:43E,60:37N \
         line_color=yellow text_color=red units=kilometers

       Geodesic line (great circle line)

NOTES

       This program works only in GRASS locations with longitude/latitude coordinate system.

SEE ALSO

        d.rhumbline, d.grid, m.measure

AUTHOR

       Michael Shapiro, U.S. Army Construction Engineering Research Laboratory

SOURCE CODE

       Available at: d.geodesic source code (history)

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       © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual