r.pi.graph
Graph Theory for connectivity analysis.
r.pi.graph [-a] input=name output=string keyval=integer distance=float neighborhood=string index=string [--overwrite] [--verbose] [--quiet] [--qq] [--ui]
Example:
r.pi.graph input=name output=string keyval=0 distance=0.0 neighborhood=nearest_neighbor index=connectance_index
grass.script.run_command("r.pi.graph", input, output, keyval, distance, neighborhood, index, flags=None, overwrite=None, verbose=None, quiet=None, superquiet=None)
Example:
gs.run_command("r.pi.graph", input="name", output="string", keyval=0, distance=0.0, neighborhood="nearest_neighbor", index="connectance_index")
grass.tools.Tools.r_pi_graph(input, output, keyval, distance, neighborhood, index, flags=None, overwrite=None, verbose=None, quiet=None, superquiet=None)
Example:
tools = Tools()
tools.r_pi_graph(input="name", output="string", keyval=0, distance=0.0, neighborhood="nearest_neighbor", index="connectance_index")
This grass.tools API is experimental in version 8.5 and expected to be stable in version 8.6.
Parameters
input=name [required]
Name of input raster map
output=string [required]
Name of the new raster file
keyval=integer [required]
Key value
distance=float [required]
Bounding distance [0 for maximum distance]
neighborhood=string [required]
Neighborhood definition
Allowed values: nearest_neighbor, relative_neighbor, gabriel, spanning_tree
index=string [required]
Cluster index
Allowed values: connectance_index, gyration_radius, cohesion_index, percent_patches, percent_area, number_patches, number_links, mean_patch_size, largest_patch_size, largest_patch_diameter, graph_diameter
-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 input raster map
Used as: input, raster, name
output : str, required
Name of the new raster file
Used as: output, raster
keyval : int, required
Key value
distance : float, required
Bounding distance [0 for maximum distance]
neighborhood : str, required
Neighborhood definition
Allowed values: nearest_neighbor, relative_neighbor, gabriel, spanning_tree
index : str, required
Cluster index
Allowed values: connectance_index, gyration_radius, cohesion_index, percent_patches, percent_area, number_patches, number_links, mean_patch_size, largest_patch_size, largest_patch_diameter, graph_diameter
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: None
verbose : bool, optional
Verbose module output
Default: None
quiet : bool, optional
Quiet module output
Default: None
superquiet : bool, optional
Very quiet module output
Default: None
input : str | np.ndarray, required
Name of input raster map
Used as: input, raster, name
output : str | type(np.ndarray) | type(np.array) | type(gs.array.array), required
Name of the new raster file
Used as: output, raster
keyval : int, required
Key value
distance : float, required
Bounding distance [0 for maximum distance]
neighborhood : str, required
Neighborhood definition
Allowed values: nearest_neighbor, relative_neighbor, gabriel, spanning_tree
index : str, required
Cluster index
Allowed values: connectance_index, gyration_radius, cohesion_index, percent_patches, percent_area, number_patches, number_links, mean_patch_size, largest_patch_size, largest_patch_diameter, graph_diameter
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: None
verbose : bool, optional
Verbose module output
Default: None
quiet : bool, optional
Quiet module output
Default: None
superquiet : bool, optional
Very quiet module output
Default: None
Returns:
result : grass.tools.support.ToolResult | np.ndarray | tuple[np.ndarray] | None
If the tool produces text as standard output, a ToolResult object will be returned. Otherwise, None
will be returned. If an array type (e.g., np.ndarray) is used for one of the raster outputs, the result will be an array and will have the shape corresponding to the computational region. If an array type is used for more than one raster output, the result will be a tuple of arrays.
DESCRIPTION
Graph Theory for connectivity analysis.
NOTES
...
EXAMPLE
An example for the North Carolina sample dataset using class 5 (forest): Computing a graph of all patches (4 neighbourhood rule) using a maximum distance of 10 pixel, the Gabriel method and as resulting index the largest patch diameter:
r.pi.graph input=landclass96 output=landclass96_graph keyval=5 distance=10 neighborhood=gabriel index=largest_patch_diameter
the results are 2 files:
landclass96_graph: the information of the index are provided (here a
range of 3-589 of patch diameter)
landclass96_graph_clusters: the generated cluster IDs are provided
(here 16 clusters are identified), doing it with a distance of 5 pixel
is resulting in a total of 66 clusters.
SEE ALSO
r.pi.corearea, r.pi.corr.mw, r.pi.csr.mw, r.pi.export, r.pi.graph.dec, r.pi.graph.pr, r.pi.graph.red, r.pi.grow, r.pi.import, r.pi.index, r.pi.lm, r.pi.odc, r.pi.prob.mw, r.pi.rectangle, r.pi
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.graph source code
(history)
Latest change: Thursday Feb 20 13:02:26 2025 in commit 53de819