NAME

       d.rhumbline  - Displays the rhumbline joining two longitude/latitude coordinates.

KEYWORDS

       display, distance, rhumbline

SYNOPSIS

       d.rhumbline
       d.rhumbline --help
       d.rhumbline coordinates=lon1,lat1,lon2,lat2  [line_color=name]   [--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

DESCRIPTION

       A  rhumbline  (loxodrome)  is  a line following a constant angle of the compass (i.e., a line of constant
       direction). It crosses all meridians at the same angle, i.e. a path  of  constant  bearing.   d.rhumbline
       displays  the  rhumbline joining any two user-specified points in the active frame on the user’s graphics
       monitor.  The named coordinate locations must fall within the boundaries of the user’s current geographic
       region.

       The  user  has  to  specify  the  starting and ending longitude/latitude coordinates of the rhumbline and
       (optionally) the color in which the rhumbline will be displayed; in  this  case,  the  program  will  run
       non-interactively.

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
       d.rhumbline coordinates=55:58W,33:18S,26:43E,60:37N \
         line_color=yellow
       # show additionally 10 degree grid
       d.grid 10

       Rhumbline (loxodrome)

NOTES

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

SEE ALSO

        d.geodesic, d.grid, m.measure

AUTHOR

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

SOURCE CODE

       Available at: d.rhumbline source code (history)

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