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 12:29:50 +0100 (Tue, 08 Nov 2011) $ Full index © 2003-2014 GRASS Development Team