NAME

       d.rhumbline   -  Displays  the  rhumbline  joining  two user-specified points, in the active frame on the
       user's graphics monitor.

KEYWORDS

       display, distance

SYNOPSIS

       d.rhumbline
       d.rhumbline help
       d.rhumbline  [coor=lon1,lat1,lon2,lat2]   [lcolor=string]   [--verbose]  [--quiet]

   Parameters:
       coor=lon1,lat1,lon2,lat2
           Starting and ending coordinates

       lcolor=string
           Line color
           Options:
           red,orange,yellow,green,blue,indigo,violet,white,black,gray,brown,magenta,aqua,grey,cyan,purple
           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  can  run  this  program  either  interactively or non-interactively.  If the user simply types
       d.rhumbline on the command line and runs it without  specifying  parameter  values,  the  mouse  will  be
       activated  and  the  user  will be asked to use the mouse to indicate the two endpoints of the rhumbline.
       The rhumbline is then drawn in the default color (black).

       Alternately, the user can 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

       g.region vect=world_political -p
       d.mon x0
       d.vect world_political type=area
       d.grid 10
       d.rhumbline coor=55:58W,33:18S,26:43E,60:37N lcolor=red

       Rhumbline (loxodrome)

NOTES

       This program works only with longitude-latitude locations.

SEE ALSO

       d.geodesic

AUTHOR

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

       Last changed: $Date: 2011-11-08 03:29:50 -0800 (Tue, 08 Nov 2011) $

       Full index

       © 2003-2013 GRASS Development Team

GRASS 6.4.3                                                                                  d.rhumbline(1grass)