QGIS algorithm - Concave hull (by feature)

Source: R/qgis_concavehullbyfeature.R

QGIS Algorithm provided by QGIS (native c++) Concave hull (by feature) (native:concavehullbyfeature). Calculates the concave hull for each feature in an input layer. This algorithm calculates the concave hull for each feature in an input layer. A concave hull is a polygon which contains all the points of the input geometries, but is a better approximation than the convex hull to the area occupied by the input. It is frequently used to convert a multi-point into a polygonal area which contains all the points from the input geometry. See the 'Concave hull (by layer)' algorithm for a concave hull calculation which covers the whole layer or grouped subsets of features.

qgis_concavehullbyfeature(
  INPUT = qgisprocess:::qgis_default_value(),
  ALPHA = qgisprocess:::qgis_default_value(),
  HOLES = qgisprocess:::qgis_default_value(),
  OUTPUT = qgisprocess:::qgis_default_value(),
  ...,
  .complete_output = .complete_output_option(),
  .quiet = .quiet_option(),
  .messages = .message_option()
)

Arguments

INPUT

source - Input layer. Path to a vector layer.

ALPHA

number - Threshold (0-1, where 1 is equivalent with Convex Hull). A numeric value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

HOLES

boolean - Allow holes. 1 for true/yes. 0 for false/no. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

OUTPUT

sink - Concave hulls. Path for new vector layer.

...

further parameters passed to qgisprocess::qgis_run_algorithm()

.complete_output

logical specifying if complete out of qgisprocess::qgis_run_algorithm() should be used (TRUE) or first output (most likely the main) should read (FALSE). Default value is TRUE.

.quiet

logical specifying if parameter .quiet for qgisprocess::qgis_run_algorithm() Default value is TRUE.

.messages

logical specifying if messages from qgisprocess::qgis_run_algorithm() should be printed (TRUE) or not (FALSE). Default value is FALSE.

Details

Outputs description

  • OUTPUT - outputVector - Concave hulls