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t.rast.univar(1grass) GRASS GIS User's Manual t.rast.univar(1grass)

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:


Calculate extended statistics

Ignore the current region settings and use the raster map regions for univar statistical calculation

Suppress printing of column names

Allow output files to overwrite existing files

Print usage summary

Verbose module output

Quiet module output

Force launching GUI dialog

Parameters:


Name of the input space time raster dataset

Raster map used for zoning, must be of type CELL

Number of threads for parallel computing
Default: 1

Name for output file

WHERE conditions of SQL statement without ’where’ keyword used in the temporal GIS framework
Example: start_time > ’2001-01-01 12:30:00’

Field separator character between the output columns
Special characters: pipe, comma, space, tab, newline
Default: pipe

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

SEE ALSO

t.create, t.info t.create,

AUTHOR

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

SOURCE CODE

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

Accessed: Friday Mar 08 07:35:36 2024

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GRASS 8.3.2