NAME
g.stats.pg - Generate a range of simple statistics for the
values in a database column. (GRASS-RDBMS General Interface Program)
SYNOPSIS
g.stats.pg
g.stats.pg help
g.stats.pg [-vf] table=name column=name [where=clause]
DESCRIPTION
g.stats.pg generates a series of simple statistics for a numeric
column in the specified table of the currently selected database. The currently
selected database is identified by the GRASS environment variable $PG_DBASE
which is set using the command g.select.pg. If this environment
variable is not set the program terminates with a message to the user.
g.stats.pg generates statistics for any numeric column in the table
specified by the user. To identify the data types for individual columns
in a table in the currently selected database use the command g.column.pg
with the -v flag. Statistics generated for the column include count,
sum, average, minimum value and maximum value.
COMMAND LINE OPTIONS
Parameters:
-
table=databasetablename
-
Name of table in currently selected database.
-
column=databasecolumnname
-
Column in [table] which is numeric in type.
where=clause
-
Clause to select only some records from table
Flags:
-v
Verbose output
-f
Use frequencies instead of min, max, mean
EXAMPLE
g.stats.pg table=utm column=ukfact
Statistics for column: ukfact
count
171
sum
47.67
avg
0.28
max
0.49
min
0.00
BUGS
None known.
NOTE
This program requires the Postgres database software.
SEE ALSO
g.column.pg, g.select.pg,
g.table.pg, d.rast.pg,
d.site.pg, d.vect.pg,
d.what.r.pg, d.what.s.pg,
d.what.v.pg, r.reclass.pg,
r.rescale.pg, v.reclass.pg
AUTHOR
Original Informix SQL-tools: James A. Farley, Wang Song, and W. Fredrick
Limp University of Arkansas, CAST
Postgres modifications: Janne Soimasuo, Faculty of Forestry, University
of Joensuu, Finland.
Updated to GRASS 5 by Alex Shevlakov (sixote@yahoo.com)