Note: A new GRASS GIS stable version has been released: GRASS GIS 7.4, available here.
Updated manual page: here
NAME
db.univar - Calculates univariate statistics on selected table column.
KEYWORDS
database,
statistics,
attribute table
SYNOPSIS
db.univar
db.univar --help
db.univar [-eg] table=name column=name [database=name] [driver=name] [where=sql_query] [percentile=float[,float,...]] [--help] [--verbose] [--quiet] [--ui]
Flags:
- -e
- Extended statistics (quartiles and 90th percentile)
- -g
- Print stats in shell script style
- --help
- Print usage summary
- --verbose
- Verbose module output
- --quiet
- Quiet module output
- --ui
- Force launching GUI dialog
Parameters:
- table=name [required]
- Name of attribute table
- column=name [required]
- Name of attribute column on which to calculate statistics (must be numeric)
- database=name
- Name of database
- driver=name
- Name of database driver
- Options: dbf, odbc, ogr, sqlite, pg
- where=sql_query
- WHERE conditions of SQL statement without 'where' keyword
- Example: income < 1000 and inhab >= 10000
- percentile=float[,float,...]
- Percentile to calculate (requires extended statistics flag)
- Options: 0-100
- Default: 90
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.
In this example, random points are sampled from the elevation map
(North Carolina sample dataset) and univariate statistics performed:
g.region raster=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
db.univar samples colum=heights
v.db.univar,
r.univar,
v.univar,
db.select,
d.vect.thematic
Michael Barton, Arizona State University
and authors of r.univar.sh
Last changed: $Date: 2014-12-19 13:55:37 -0800 (Fri, 19 Dec 2014) $
SOURCE CODE
Available at: db.univar source code (history)
Note: A new GRASS GIS stable version has been released: GRASS GIS 7.4, available here.
Updated manual page: here
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© 2003-2018
GRASS Development Team,
GRASS GIS 7.0.7svn Reference Manual