.TH v.qcount 1grass "" "GRASS 6.4.4" "Grass User's Manual"
.SH NAME
\fI\fBv.qcount\fR\fR  - Indices for quadrat counts of sites lists.
.SH KEYWORDS
vector, statistics
.SH SYNOPSIS
\fBv.qcount\fR
.br
\fBv.qcount help\fR
.br
\fBv.qcount\fR [\-\fBgq\fR] \fBinput\fR=\fIstring\fR  [\fBoutput\fR=\fIstring\fR]  \fBn\fR=\fIinteger\fR \fBr\fR=\fIfloat\fR  [\-\-\fBoverwrite\fR]  [\-\-\fBverbose\fR]  [\-\-\fBquiet\fR] 
.SS Flags:
.IP "\fB\-g\fR" 4m
.br
Print results in shell script style
.IP "\fB\-q\fR" 4m
.br
Quiet
.IP "\fB\-\-overwrite\fR" 4m
.br
Allow output files to overwrite existing files
.IP "\fB\-\-verbose\fR" 4m
.br
Verbose module output
.IP "\fB\-\-quiet\fR" 4m
.br
Quiet module output
.PP
.SS Parameters:
.IP "\fBinput\fR=\fIstring\fR" 4m
.br
Vector of points defining sample points
.IP "\fBoutput\fR=\fIstring\fR" 4m
.br
Output quadrant centres, number of points is written as category
.IP "\fBn\fR=\fIinteger\fR" 4m
.br
Number of quadrats
.IP "\fBr\fR=\fIfloat\fR" 4m
.br
Quadrat radius
.PP
.SH DESCRIPTION
\fIv.qcount\fR chooses \fBn\fR circular quadrats of
radius \fBr\fR such that they are completely within the
bounds of the current region and no two quadrats overlap.
The number of points falling within each quadrat are counted
and indices are calculated to estimate the departure of
point locations from complete spatial randomness.
.SH NOTES
This program may not work properly with lat-long data. It uses 
\fIhypot()\fR
in two files: \fIcount.c\fR and \fIfindquads.c\fR.
.SH SEE ALSO
\fIv.random\fR 
.PP
\fIComplete Spatial Randomness and Quadrat Methods\fR  - 
GRASS Tutorial on \fIv.qcount\fR
(only available as older file s.qcount-tutorial.ps),
.PP
General references include:
.br
Noel A. C. Cressie.
\fIStatistics for Spatial Data\fR.
Wiley Series in Probability and Mathematical Statistics. John Wiley
& Sons, New York, NY, 1st edition, 1991.
.br
Brian D. Ripley.
\fISpatial Statistics\fR. John Wiley \(rs& Sons, New York, NY, 1981.
.PP
References to the indices include:
.br
F. N. David and P. G. Moore.
Notes on contagious distributions in plant populations.
\fIAnnals of Botany\fR, 18:47-53, 1954.
.br
J. B. Douglas.  Clustering and aggregation.
\fISankhya B\fR, 37:398-417, 1975.
.br
R. A. Fisher, H. G. Thornton, and W. A. Mackenzie.
The accuracy of the plating method of estimating the density of
bacterial populations.
\fIAnnals of Applied Biology\fR, 9:325-359, 1922.
.br
M. Lloyd. Mean crowding.
\fIJournal of Animal Ecology\fR, 36:1-30, 1967.
.br
M. Morista. Measuring the dispersion and analysis of distribution patterns.
\fIMemoires of the Faculty of Science, Kyushu University, Series E.
Biology\fR, 2:215-235, 1959.
.SH BUGS
.PP
Timestamp not working for header part of counts output. (2000-10-28)
.PP
Please send all bug fixes and comments to the author
or the grass development team. 
.br
http://grass.osgeo.org.
.SH AUTHORS
James Darrell McCauley
,
.br
when he was at: 
Agricultural Engineering
Purdue University
.PP
Modified for GRASS 5.0 by Eric G. Miller (2000-10-28)
.br
Modified for GRASS 5.7 by R. Blazek (2004-10-14)
.PP
\fILast changed: $Date: 2011-11-08 10:42:51 +0100 (Tue, 08 Nov 2011) $\fR
.PP
Full index
.PP
© 2003-2014 GRASS Development Team