
NAME
v.univar - Calculates univariate statistics for attribute.
Variance and standard deviation is calculated only for points if specified.
KEYWORDS
vector, statistics
SYNOPSIS
v.univar
v.univar help
v.univar [-ge] map=name layer=string [type=string[,string,...]] column=name [where=sql_query] [percentile=integer] [--verbose] [--quiet]
Flags:
- -g
- Print the stats in shell script style
- -e
- Calculate extended statistics
- --verbose
- Verbose module output
- --quiet
- Quiet module output
Parameters:
- map=name
- Name of vector map
- Data source for direct OGR access
- layer=string
- Layer number or name
- A single vector map can be connected to multiple database tables. This number determines which table to use. Layer name for direct OGR access.
- Default: 1
- type=string[,string,...]
- Feature type
- Options: point,line,boundary,centroid,area
- Default: point,line,boundary,centroid,area
- column=name
- Name of attribute column
- where=sql_query
- WHERE conditions of SQL statement without 'where' keyword
- Example: income < 1000 and inhab >= 10000
- percentile=integer
- Percentile to calculate (requires extended statistics flag)
- Options: 0-100
- Default: 90
DESCRIPTION
v.univar calculates univariate statistics of vector map features.
This includes the number of features counted, minimum and maximum values,
and range.
Variance and standard deviation is calculated only for points if
type=point is defined.
Extended statistics adds median, 1st and 3rd quartiles, and 90th
percentile.
EXAMPLE
g.region rast=elevation.10m -p
v.random out=samples n=100
v.db.addtable samples col="heights double precision"
v.what.rast samples rast=elevation.10m col=heights
v.db.select samples
v.univar samples col=heights type=point
SEE ALSO
v.neighbors
AUTHOR
Radim Blazek, ITC-irst
Last changed: $Date: 2008-08-14 23:16:42 -0700 (Thu, 14 Aug 2008) $
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