## NAME

db.univar.py - Calculates univariate statistics on selected table column.

## KEYWORDS

database, statistics, attribute table

## SYNOPSIS

db.univar.py
db.univar.py --help
db.univar.py [-eg] table=name column=name [database=name] [driver=name] [where=sql_query] [percentile=float[,float,...]] [format=string] [--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 population >= 10000
percentile=float[,float,...]
  Percentile to calculate (requires extended statistics flag)
  Options: 0-100
  Default: 90
format=string
  Output format
  Options: plain, json, shell
  plain: Plain text output
  json: JSON (JavaScript Object Notation)
  shell: Shell script style for Bash eval

## 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)

Accessed: Sunday Apr 14 02:04:37 2024

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