NAME

       v.db.univar  - Calculates univariate statistics on selected table column for a GRASS vector map.

KEYWORDS

       vector, statistics

SYNOPSIS

       v.db.univar
       v.db.univar help
       v.db.univar   [-e]   table=string  column=string   [database=string]    [driver=string]    [where=string]
       [--verbose]  [--quiet]

   Flags:
       -e
           Extended statistics (quartiles and 90th percentile)

       --verbose
           Verbose module output

       --quiet
           Quiet module output

   Parameters:
       table=string
           Name of data table

       column=string
           Column on which to calculate statistics (must be numeric)

       database=string
           Database/directory for table

       driver=string
           Database driver

       where=string
           WHERE conditions of SQL statement without 'where' keyword

DESCRIPTION

       v.db.univar calculates basic univariate statistics for numeric  attributes  in  a  data  table.  It  will
       calculate  minimum,  maximum,  range,  mean,  standard  deviation,  variance,  coefficient  of variation,
       quartiles, median, and 90th percentile.   It  uses  db.select  to  create  list  values  for  statistical
       calculations.   NOTES  If the database and driver are not specified, the default values set in db.connect
       will be used.

EXAMPLE

       In this example, random points are sampled from the elevation map (North  Carolina  sample  dataset)  and
       univariate statistics performed:
       g.region rast=elevation -p
       v.random output=samples n=100
       v.db.addtable samples column="heights double precision"
       v.what.rast samples raster=elevation colum=heights
       v.db.select samples
       v.db.univar samples colum=heights

SEE ALSO

        r.univar, v.univar,, db.select, d.vect.thematic

AUTHOR

       Michael Barton, Arizona State University

       and authors of r.univar.sh

       Last changed: $Date: 2011-09-04 06:23:30 -0700 (Sun, 04 Sep 2011) $

       Full index

       © 2003-2013 GRASS Development Team

GRASS 6.4.3                                                                                  v.db.univar(1grass)