Geografic-Information-System/display/d.rhumbline/d.rhumbline.html

<h2>DESCRIPTION</h2>

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.

 <!-- There are 32
points on the compass (points are roughly 11 degrees 15
minutes apart). --> <em>d.rhumbline</em> 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.

<p>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.

<h2>EXAMPLE</h2>

<div class="code"><pre>
g.region vect=world_political -p
d.mon wx0
d.vect world_political type=area
d.rhumbline coor=55:58W,33:18S,26:43E,60:37N lcolor=yellow tcolor=red
</pre></div>

<p><center>
<img src="d_rhumbline.png" border=1><br>
<i>Rhumbline (loxodrome)</i>
</center>


<h2>NOTES</h2>

This program works only with longitude-latitude locations. 

<h2>SEE ALSO</h2>

<em><a href="d.geodesic.html">d.geodesic</a></em>

<h2>AUTHOR</h2>

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

<p><i>Last changed: $Date$</i>