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

GRASS logo

NAME

r.jpdf - From two series of input raster maps, calculates the joint probability function and outputs the probabilities of occurrence in the specified bins.

KEYWORDS

raster, series

SYNOPSIS

r.jpdf
r.jpdf --help
r.jpdf [-q] output=name input1=string[,string,...] input2=string[,string,...] bins1=string[,string,...] bins2=string[,string,...] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

-q
Run quietly
--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:

output=name [required]
Prefix of output raster name, will be followed by bin numbers
input1=string[,string,...] [required]
First set of input rasters
input2=string[,string,...] [required]
Second set of input rasters
bins1=string[,string,...] [required]
Start value, end value, and number of bins for first independent variable (from first set of inputs)
bins2=string[,string,...] [required]
Start value, end value, and number of bins for second independent variable (from second set of inputs)

Table of contents

DESCRIPTION

r.jpdf reads two series of raster maps and calculates for each raster cell the joint probability density function of the two input series. The output is set of raster maps, each containing the probability within a range of values from the first set and a range from the second set. NULL values are ignored when calculating the JPDF.

The number of output raster maps is determined by the number of "bins" specified by the user using the parameters input1 and input2. The users gives the range and density of bins with input1=Start1,End1,Nbins1 input2=Start2,End2,Nbins2. In this case the data from the first data set will be assigned to Nbins1 intervals between Start1 and End1 and Nbins2 intervals between Start2 and End2 for the second data set. In addition, r.jpdf will calculate extra bins for values below or above the start and end values given by the user. In total, the output will consist of (Nbins1+2)×(Nbins2+2) raster maps. The naming of the output rasters is Prefix_N1_N2 where Prefix is given by the parameter output. N1 and N2 may contain leading zeros.

NOTES

Input series of different lengths

Rasters from the two series of input data will be compared in the order in which they appear in the two lists. If one list is longer than the other, the trailing raster maps will be ignored.

Memory consumption

The (Nbins1+2)×(Nbins2+2) raster maps are held in memory until the end of the processing. On the other hand, only one raster from each of the two series of input rasters will be held in memory.

EXAMPLES

Using r.jpdf with wildcards: 
r.series input1="`g.list pattern='temperature*' sep=,`" input2="`g.list pattern='pressure*' sep=,`"\
         output=jpdf_temp_pres bins1=-20,40,10 bins2=950,1030,10

Note the g.list script also supports regular expressions for selecting map names.

SEE ALSO

g.list, g.region, r.quantile, r.series.accumulate, r.series.interp, r.univar

Hints for large raster data processing

AUTHOR

Thomas Huld

SOURCE CODE

Available at: r.jpdf source code (history)

Latest change: Monday Jun 28 07:54:09 2021 in commit: 1cfc0af029a35a5d6c7dae5ca7204d0eb85dbc55

Main index | Raster index | Topics index | Keywords index | Graphical index | Full index

© 2003-2023 GRASS Development Team, GRASS GIS 7.8.9dev Reference Manual