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

<h2>DESCRIPTION</h2>

<em>d.where</em> is an <em>interactive</em> program that
allows the user, using the pointing device (mouse), to
identify the geographic coordinates associated with point
locations within the current geographic region in the
active display frame on the graphics monitor.

<p>Each mouse click will output the easting and northing of the point
currently located beneath the mouse pointer. 
A mouse-button menu is presented so the user knows which
mouse buttons to use. The output is always printed to the
terminal screen; if the output is redirected into a file,
it will be written to the file as well.

<p>Mouse buttons:

<div class="code"><pre>
     Left:   where am i
     Middle: draw to/from here
     Right:  quit this
</pre></div>

The left mouse button prints the coordinates at the selected point,
the middle mouse button allows you to query two points (they are connected
by a line for convenience). Use the right mouse button to exit the module.


<h2>NOTES</h2>

This program uses the current geographic region setting and active frame. 
It is not necessary, although useful, to have displayed a map in the current 
frame before running <em>d.where</em>. The <b>-d</b> flag allows the user to
optionally output latitude/longitude coordinates pair(s) in decimal degree
rather than DD:MM:SS format. The <b>-w</b> flag is only valid
if a datum is defined for the current location.

If the <b>-f</b> flag is given the x,y frame coordinates of the active display 
monitor will be returned (as a percentage, 0,0 is bottom left).

<h2>EXAMPLE</h2>

Query position in map (North Carolina sample dataset):
<div class="code"><pre>
d.rast elevation
d.where
</pre></div>

<h2>SEE ALSO</h2>

<em>
<a href="d.what.rast.html">d.what.rast</a>,
<a href="d.what.vect.html">d.what.vect</a>,
<a href="g.region.html">g.region</a>,
<a href="v.what.rast.html">v.what.rast</a>,
<a href="v.what.vect.html">v.what.vect</a>
</em>


<h2>AUTHORS</h2>

James Westervelt, <br>
Michael Shapiro, <br>
U.S. Army Construction Engineering 
Research Laboratory

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