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: