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,...]] [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
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 column=heights
v.db.select samples
db.univar samples column=heights
v.db.univar,
r.univar,
v.univar,
db.select,
d.vect.thematic
Michael Barton, Arizona State University
and authors of r.univar.sh
SOURCE CODE
Available at:
db.univar source code
(history)
Latest change: Monday Oct 21 17:07:17 2024 in commit: 67a160931aa01d29a896def827d5dd687e08bfd4
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GRASS Development Team,
GRASS GIS 8.5.0dev Reference Manual