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v.concave.hull

Creates a concave hull around points.

v.concave.hull input=name output=name [threshold=float] [--overwrite] [--verbose] [--quiet] [--qq] [--ui]

Example:

v.concave.hull input=name output=name

grass.script.run_command("v.concave.hull", input, output, threshold=7, overwrite=None, verbose=None, quiet=None, superquiet=None)

Example:

gs.run_command("v.concave.hull", input="name", output="name")

grass.tools.Tools.v_concave_hull(input, output, threshold=7, overwrite=None, verbose=None, quiet=None, superquiet=None)

Example:

tools = Tools()
tools.v_concave_hull(input="name", output="name")

This grass.tools API is experimental in version 8.5 and expected to be stable in version 8.6.

Parameters

input=name [required]
    Input points
    Or data source for direct OGR access
output=name [required]
    Name for output vector map
threshold=float
    Lower values make the hull more concave
    Allowed values: 0-10
    Default: 7
--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
    Input points
    Or data source for direct OGR access
    Used as: input, vector, name
output : str, required
    Name for output vector map
    Used as: output, vector, name
threshold : float, optional
    Lower values make the hull more concave
    Allowed values: 0-10
    Default: 7
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, required
    Input points
    Or data source for direct OGR access
    Used as: input, vector, name
output : str, required
    Name for output vector map
    Used as: output, vector, name
threshold : float, optional
    Lower values make the hull more concave
    Allowed values: 0-10
    Default: 7
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 | None
If the tool produces text as standard output, a ToolResult object will be returned. Otherwise, None will be returned.

DESCRIPTION

v.concave.hull creates a concave hull around points. Contrary to a convex hull, a concave hull can describe the shape of a point cloud.

EXAMPLES

Creating a convex and a concave hull

Creating a convex and a concave hull around schools_wake in the North Carolina sample dataset:

v.hull in=schools_wake out=schools_wake_convex
v.concave.hull in=schools_wake out=schools_wake_concave

Convex hull around schools:

image-alt

Concave hull around schools:

image-alt

Creating Alpha shapes

Alpha shapes around points (left: threshold=8; right: threshold=0.5):

image-alt   image-alt

SEE ALSO

v.hull, v.buffer,, v.kernel

AUTHOR

Markus Metz

SOURCE CODE

Available at: v.concave.hull source code (history)
Latest change: Thursday Feb 20 13:02:26 2025 in commit 53de819