Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon manual page.
NAME
r.pi.import - Import and generation of patch raster data
KEYWORDS
raster
SYNOPSIS
r.pi.import
r.pi.import --help
r.pi.import [-a] input=string raster=name output=name keyval=integer id_col=integer val_col=integer [title="phrase"] [--overwrite] [--help] [--verbose] [--quiet] [--ui]
Flags:
- -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
- --ui
- Force launching GUI dialog
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
Import and generation of patch raster data based on individual patch
based raster data.
...
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
r.pi.export,
r.pi
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: Mon Jun 28 07:54:09 2021 in commit: 1cfc0af029a35a5d6c7dae5ca7204d0eb85dbc55
Note: This addon document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade your GRASS GIS installation, and read the current addon manual page.
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GRASS Development Team,
GRASS GIS 7.8.8dev Reference Manual