table of contents
db.univar(1grass) | GRASS GIS User's Manual | db.univar(1grass) |
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:¶
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
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 Jan 22 07:37:42 2023
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