3
<em>v.qcount</em> chooses <b>n</b> circular quadrats of
4
radius <b>r</b> such that they are completely within the
5
bounds of the current region and no two quadrats overlap.
6
The number of points falling within each quadrat are counted
7
and indices are calculated to estimate the departure of
8
point locations from complete spatial randomness.
12
This program may not work properly with lat-long data. It uses
14
in two files: <em>count.c</em> and <em>findquads.c</em>.
18
<em><a href="v.random.html">v.random</a></em>
21
<em>Complete Spatial Randomness and Quadrat Methods</em> -
22
GRASS Tutorial on <em>v.qcount</em>
23
(only available as older file s.qcount-tutorial.ps),
26
General references include:
30
<em>Statistics for Spatial Data</em>.
31
Wiley Series in Probability and Mathematical Statistics. John Wiley
32
& Sons, New York, NY, 1st edition, 1991.
36
<em>Spatial Statistics</em>. John Wiley \& Sons, New York, NY, 1981.
39
References to the indices include:
42
F. N. David and P. G. Moore.
43
Notes on contagious distributions in plant populations.
44
<em>Annals of Botany</em>, 18:47-53, 1954.
47
J. B. Douglas. Clustering and aggregation.
48
<em>Sankhya B</em>, 37:398-417, 1975.
51
R. A. Fisher, H. G. Thornton, and W. A. Mackenzie.
52
The accuracy of the plating method of estimating the density of
53
bacterial populations.
54
<em>Annals of Applied Biology</em>, 9:325-359, 1922.
57
M. Lloyd. Mean crowding.
58
<em>Journal of Animal Ecology</em>, 36:1-30, 1967.
61
M. Morista. Measuring the dispersion and analysis of distribution patterns.
62
<em>Memoires of the Faculty of Science, Kyushu University, Series E.
63
Biology</em>, 2:215-235, 1959.
67
Timestamp not working for header part of counts output. (2000-10-28)
69
Please send all bug fixes and comments to the author
70
or the grass development team. <br>
71
<a href="http://grass.osgeo.org"><tt>http://grass.osgeo.org</tt></a>.
75
<a href="http://mccauley-usa.com/">James Darrell McCauley</a>
76
<a href="mailto:darrell@mccauley-usa.com"><darrell@mccauley-usa.com></a>,
78
<a href="http://ABE.www.ecn.purdue.edu/ABE/">Agricultural Engineering</a>
79
<a href="http://www.purdue.edu/">Purdue University</a>
82
Modified for GRASS 5.0 by Eric G. Miller (2000-10-28)
84
Modified for GRASS 5.7 by R. Blazek (2004-10-14)
87
<p><i>Last changed: $Date: 2011-11-08 10:42:51 +0100 (Tue, 08 Nov 2011) $</i>