r.pi.import
Import and generation of patch raster data
r.pi.import [-a] input=string raster=name output=name keyval=integer id_col=integer val_col=integer [title="phrase"] [--overwrite] [--verbose] [--quiet] [--qq] [--ui]
Example:
r.pi.import input=string raster=name output=name keyval=integer id_col=integer val_col=integer
grass.script.run_command("r.pi.import", input, raster, output, keyval, id_col, val_col, title=None, flags=None, overwrite=False, verbose=False, quiet=False, superquiet=False)
Example:
gs.run_command("r.pi.import", input="string", raster="name", output="name", keyval=integer, id_col=integer, val_col=integer)
Parameters
input=string [required]
Name of the input ASCII-file
raster=name [required]
Name of input raster map
output=name [required]
Name for output raster map
keyval=integer [required]
Category value of the patches
id_col=integer [required]
Number of the column with patch IDs
val_col=integer [required]
Number of the column with patch values
title="phrase"
Title for resultant raster map
-a
Set for 8 cell-neighbors. 4 cell-neighbors are default
--overwrite
Allow output files to overwrite existing files
--help
Print usage summary
--verbose
Verbose module output
--quiet
Quiet module output
--qq
Very quiet module output
--ui
Force launching GUI dialog
input : str, required
Name of the input ASCII-file
Used as: input
raster : str, required
Name of input raster map
Used as: input, raster, name
output : str, required
Name for output raster map
Used as: output, raster, name
keyval : int, required
Category value of the patches
id_col : int, required
Number of the column with patch IDs
val_col : int, required
Number of the column with patch values
title : str, optional
Title for resultant raster map
Used as: "phrase"
flags : str, optional
Allowed values: a
a
Set for 8 cell-neighbors. 4 cell-neighbors are default
overwrite: bool, optional
Allow output files to overwrite existing files
Default: False
verbose: bool, optional
Verbose module output
Default: False
quiet: bool, optional
Quiet module output
Default: False
superquiet: bool, optional
Very quiet module output
Default: False
DESCRIPTION
Import and generation of patch raster data based on individual patch based raster data.
NOTES
...
EXAMPLE
An example for the North Carolina sample dataset: In order to run r.pi.import we need an exported patch index raster:
r.pi.index input=landclass96 output=landclass96_forestclass5_area keyval=5 method=area
export this resulting map:
r.pi.export input=landclass96_forestclass5_area output=patch_area_out values=patch_area_values id_raster=forestclass5_ID stats=average,variance,min
modify it with R or just import the file again and assign the percentage coverage to each fragment. You need the patch_area_values file and the previously used input file forestclass96 raster (important: the same patch coverage is mandatory otherwise patch ID in the text file and raster are not congruent!):
r.pi.import input=patch_area_values raster=landclass96 output=imported_values keyval=5 id_col=1 val_col=2
if you want to export the patch values to R and do e.g. a linear
regression of two patch values and import them again in GRASS, do:
apply r.pi.export with two indices (A and B), in R, do:
resid.AB <- resid(lm(A[,3]~B[,3])) #write residuals of a linear regression
df.resid.AB <- data.frame(A[,1],resid.AB) #merge patch IDs and resid into same data frame
write.table(df.resid.AB,"resid.for.GRASS",row.names=F,col.names=F)
exit R and run in GRASS:
r.pi.import input=resid.for.GRASS raster=landclass96 output=resid.AB keyval=5 id_col=1 val_col=2
SEE ALSO
AUTHORS
Programming: Elshad Shirinov
Scientific concept: Dr. Martin Wegmann
Department of Remote Sensing
Remote Sensing and Biodiversity Unit
University of Wuerzburg, Germany
Port to GRASS GIS 7: Markus Metz
SOURCE CODE
Available at: r.pi.import source code
(history)
Latest change: Thursday Mar 20 21:36:57 2025 in commit 7286ecf