t.rast.univar - GRASS GIS manual

Note: This document is for an older version of GRASS GIS that has been discontinued. You should upgrade, and read the current manual page.

NAME

t.rast.univar - Calculates univariate statistics from the non-null cells for each registered raster map of a space time raster dataset.

KEYWORDS

temporal, statistics, raster, time, parallel

SYNOPSIS

t.rast.univar

t.rast.univar --help

t.rast.univar [-eru] input=name [zones=name] [nprocs=integer] [output=name] [where=sql_query] [separator=character] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

-e: Calculate extended statistics
-r: Ignore the current region settings and use the raster map regions for univar statistical calculation
-u: Suppress printing of column names
--overwrite: Allow output files to overwrite existing files
--help: Print usage summary
--verbose: Verbose module output
--quiet: Quiet module output
--ui: Force launching GUI dialog

Parameters:

input=name [required]: Name of the input space time raster dataset
zones=name: Raster map used for zoning, must be of type CELL
nprocs=integer: Number of threads for parallel computing; Default: 1
output=name: Name for output file
where=sql_query: WHERE conditions of SQL statement without 'where' keyword used in the temporal GIS framework; Example: start_time > '2001-01-01 12:30:00'
separator=character: Field separator character between the output columns; Special characters: pipe, comma, space, tab, newline; Default: pipe

DESCRIPTION
EXAMPLE
SEE ALSO
AUTHOR

DESCRIPTION

t.rast.univar calculates univariate statistics from the non-null cells for each registered raster map of a space time raster dataset.

By default it returns the name of the map, the start and end date of dataset and the following values: mean, minimum and maximum vale, mean_of_abs, standard deviation, variance, coeff_var, number of null cells, total number of cells.

Using the e flag it can calculate also extended statistics: first quartile, median value, third quartile and percentile 90.

If a zones raster map is provided, statistics are computed for each zone (category) in that input raster map. The zones option does not support Spatio-Temporal-Raster-Datasets (STRDS) but only a single, static raster map.

EXAMPLE

Obtain the univariate statistics for the raster space time dataset "tempmean_monthly" (precision reduced to 2 decimals in this example):

t.rast.univar -e tempmean_monthly
id|start|end|mean|min|max|mean_of_abs|stddev|variance|coeff_var|sum|null_cells|cells|first_quartile|median|third_quartile|percentile_90
2009_01_tempmean@climate_2009_2012|2009-01-01 00:00:00|2009-02-01 00:00:00|3.90|-3.38|7.43|3.95|1.79|3.20|45.91|1977967.31|503233|1010600|2.80|3.92|5.21|6.23
2009_02_tempmean@climate_2009_2012|2009-02-01 00:00:00|2009-03-01 00:00:00|5.91|-1.82|8.01|5.92|1.63|2.65|27.53|2999555.60|503233|1010600|5.44|6.26|7.07|7.48
...
2012_11_tempmean@climate_2009_2012|2012-11-01 00:00:00|2012-12-01 00:00:00|8.03|1.79|10.91|8.03|1.32|1.73|16.41|4072472.77|503233|1010600|7.49|8.13|8.96|9.48
2012_12_tempmean@climate_2009_2012|2012-12-01 00:00:00|2013-01-01 00:00:00|8.71|1.76|11.98|8.71|1.72|2.95|19.74|4418403.77|503233|1010600|7.84|8.95|9.99|10.67

AUTHOR

Sören Gebbert, Thünen Institute of Climate-Smart Agriculture Stefan Blumentrath, (Support for zones)

SOURCE CODE

Available at: t.rast.univar source code (history)

Latest change: Wednesday Mar 01 21:08:00 2023 in commit: 1a96f69ccf430caa03bec8dbfc990c07c81f3164