s.qcount <contrib>    GRASS Reference Manual   <contrib> s.qcount



NAME
     s.qcount - indices for quadrat counts of sites lists
     (GRASS Sites Program)

SYNOPSIS
     s.qcount
     s.qcount help
     s.qcount [-ciq] input=name n=value r=value

DESCRIPTION
     s.qcount chooses n circular quadrats of radius r such that
     they are completely within the bounds of the current region
     and no two quadrats overlap. The number of sites falling
     within each quadrat are counted and indices are calculated
     to estimate the departure of site locations from complete
     spatial randomness.

OPTIONS
     Flags:

     -c		       Print count data for each quadrat in the
		       form of a sites list (E|N|#n desc, where E
		       is the easting and N is the northing of
		       the quadrat center, n is the quadrat
		       number, and desc is an integer indicating
		       the number of sites contained within the
		       quadrat).

     -i		       Suppress printing table of indices
		       (default is to print indices and not the
		       count data).

     -q		       Quiet. Cut out the chatter.

     Parameters:

     input=name	       Name of sites list defining qcount points.

     n=value	       Number of quadrats (integer).

     r=value	       Radius of quadrats (floating point).

NOTES
     This program may not work properly with lat-long data. It
     uses hypot() in two files: count.c and findquads.c.

SEE ALSO
     s.rand and
     Complete Spatial Randomness and Quadrat Methods - GRASS
     Tutorial on s.qcount (available as s.qcount-tutorial.ps),





GRASS 5.0beta6	      GRASS Development Team			1






s.qcount <contrib>    GRASS Reference Manual   <contrib> s.qcount



     General references include:
     Noel A. C. Cressie.  Statistics for Spatial Data.	Wiley
     Series in Probability and Mathematical Statistics. John
     Wiley & Sons, New York, NY, 1st edition, 1991.
     Brian D. Ripley.  Spatial Statistics.  John Wiley	Sons, New
     York, NY, 1981.

     References to the indices include:
     F. N. David and P. G. Moore.  Notes on contagious
     distributions in plant populations.  Annals of Botany,
     18:47-53, 1954.
     J. B. Douglas.  Clustering and aggregation.  Sankhya B,
     37:398-417, 1975.
     R. A. Fisher, H. G. Thornton, and W. A. Mackenzie.	 The
     accuracy of the plating method of estimating the density of
     bacterial populations.  Annals of Applied Biology,
     9:325-359, 1922.
     M. Lloyd.	Mean crowding.	Journal of Animal Ecology,
     36:1-30, 1967.
     M. Morista.  Measuring the dispersion and analysis of
     distribution patterns.  Memoires of the Faculty of Science,
     Kyushu University, Series E.  Biology, 2:215-235, 1959.

BUGS
     Please send all bug fixes and comments to the author.

AUTHOR
     James Darrell McCauley, Agricultural Engineering, Purdue
     University
     (mccauley@ecn.purdue.edu)

NOTICE
     This program is part of the contrib section of the GRASS
     distribution.  As such, it is externally contributed code
     that has not been examined or tested by the Office of GRASS
     Integration.



















2		      GRASS Development Team	   GRASS 5.0beta6