qgis_extractspecificvertices: QGIS algorithm - Extract specific vertices

In JanCaha/r_package_qgis: An extension of package "qgisprocess" providing direct R functions for QGIS functions

QGIS algorithm - Extract specific vertices

Description

QGIS Algorithm provided by QGIS (native c++) Extract specific vertices (native:extractspecificvertices). This algorithm takes a vector layer and generates a point layer with points representing specific vertices in the input geometries. For instance, this algorithm can be used to extract the first or last vertices in the geometry. The attributes associated to each point are the same ones associated to the feature that the point belongs to. The vertex indices parameter accepts a comma separated string specifying the indices of the vertices to extract. The first vertex corresponds to an index of 0, the second vertex has an index of 1, etc. Negative indices can be used to find vertices at the end of the geometry, e.g., an index of -1 corresponds to the last vertex, -2 corresponds to the second last vertex, etc. Additional fields are added to the points indicating the specific vertex position (e.g., 0, -1, etc), the original vertex index, the vertex’s part and its index within the part (as well as its ring for polygons), distance along the original geometry and bisector angle of vertex for the original geometry. —————- Notes —————- - This algorithm drops existing primary keys or FID values and regenerates them in output layers.

Usage

qgis_extractspecificvertices(
  INPUT = qgisprocess:::qgis_default_value(),
  VERTICES = 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.
VERTICES	string - Vertex indices. String 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.
OUTPUT	sink - Vertices. 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 - Vertices

JanCaha/r_package_qgis documentation built on Nov. 3, 2024, 5:25 p.m.