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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