GRASS GIS: v.db.univar

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. (GRASS Shell Script)

NOTES

If the database and driver are not specified, the default values set in db.connect will be used.

EXAMPLE

g.region rast=elevation.10m -p
v.random out=samples n=100
v.db.addtable samples col="heights double precision"
v.what.rast samples rast=elevation.10m col=heights
v.db.select samples

v.db.univar samples col=heights

AUTHOR

Michael Barton, Arizona State University

and authors of r.univar.sh

Last changed: $Date: 2008-03-13 01:01:14 -0700 (Thu, 13 Mar 2008) $

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