db.univar
Calculates univariate statistics on selected table column.
db.univar [-eg] table=name column=name [database=name] [driver=name] [where=sql_query] [percentile=float [,float,...]] [format=string] [--verbose] [--quiet] [--qq] [--ui]
Example:
db.univar table=name column=name
grass.script.parse_command("db.univar", table, column, database=None, driver=None, where=None, percentile=90, format=None, flags=None, verbose=False, quiet=False, superquiet=False)
Example:
gs.parse_command("db.univar", table="name", column="name")
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
Allowed values: dbf, odbc, ogr, sqlite, pg
where=sql_query
WHERE conditions of SQL statement without 'where' keyword
Example: income < 1000 and population >= 10000
percentile=float [,float,...]
Percentile to calculate (requires extended statistics flag)
Allowed values: 0-100
Default: 90
format=string
Output format
Allowed values: plain, json, shell
plain: Plain text output
json: JSON (JavaScript Object Notation)
shell: Shell script style for Bash eval
-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
--qq
Very quiet module output
--ui
Force launching GUI dialog
table : str, required
Name of attribute table
Used as: input, dbtable, name
column : str, required
Name of attribute column on which to calculate statistics (must be numeric)
Used as: input, dbcolumn, name
database : str, optional
Name of database
Used as: input, dbname, name
driver : str, optional
Name of database driver
Used as: input, dbdriver, name
Allowed values: dbf, odbc, ogr, sqlite, pg
where : str, optional
WHERE conditions of SQL statement without 'where' keyword
Example: income < 1000 and population >= 10000
Used as: input, sql_query, sql_query
percentile : float | list[float] | str, optional
Percentile to calculate (requires extended statistics flag)
Allowed values: 0-100
Default: 90
format : str, optional
Output format
Allowed values: plain, json, shell
plain: Plain text output
json: JSON (JavaScript Object Notation)
shell: Shell script style for Bash eval
flags : str, optional
Allowed values: e, g
e
Extended statistics (quartiles and 90th percentile)
g
Print stats in shell script style
verbose: bool, optional
Verbose module output
Default: False
quiet: bool, optional
Quiet module output
Default: False
superquiet: bool, optional
Very quiet module output
Default: False
DESCRIPTION
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 raster=elevation -p
v.random output=samples n=100
v.db.addtable samples column="heights double precision"
v.what.rast samples raster=elevation column=heights
v.db.select samples
db.univar samples column=heights
SEE ALSO
v.db.univar, r.univar, v.univar, db.select, d.vect.thematic
AUTHORS
Michael Barton, Arizona State University
and authors of r.univar.sh
SOURCE CODE
Available at: db.univar source code
(history)
Latest change: Saturday Apr 12 00:27:09 2025 in commit 548797c