QGIS algorithm - Valley and ridge detection (top hat approach)

Source: R/sagang_valleyandridgedetectiontophatapproach.R

QGIS Algorithm provided by SAGA Next Gen Valley and ridge detection (top hat approach) (sagang:valleyandridgedetectiontophatapproach). ---------------- Arguments ---------------- DEM: Elevation Argument type: raster Acceptable values: - Path to a raster layer VALLEY: Valley Depth Argument type: rasterDestination Acceptable values: - Path for new raster layer HILL: Hill Height Argument type: rasterDestination Acceptable values: - Path for new raster layer VALLEY_IDX: Valley Index Argument type: rasterDestination Acceptable values: - Path for new raster layer HILL_IDX: Hill Index Argument type: rasterDestination Acceptable values: - Path for new raster layer SLOPE_IDX: Hillslope Index Argument type: rasterDestination Acceptable values: - Path for new raster layer RADIUS_VALLEY: Valley Radius Default value: 1000 Argument type: number Acceptable values: - 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 RADIUS_HILL: Hill Radius Default value: 1000 Argument type: number Acceptable values: - 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 THRESHOLD: Elevation Threshold Default value: 100 Argument type: number Acceptable values: - 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 METHOD: Slope Index Default value: 0 Argument type: enum Available values: - 0: (0) default - 1: (1) alternative Acceptable values: - Number of selected option, e.g. '1' - Comma separated list of options, e.g. '1,3'

sagang_valleyandridgedetectiontophatapproach(
  DEM = qgisprocess:::qgis_default_value(),
  VALLEY = qgisprocess:::qgis_default_value(),
  HILL = qgisprocess:::qgis_default_value(),
  VALLEY_IDX = qgisprocess:::qgis_default_value(),
  HILL_IDX = qgisprocess:::qgis_default_value(),
  SLOPE_IDX = qgisprocess:::qgis_default_value(),
  RADIUS_VALLEY = qgisprocess:::qgis_default_value(),
  RADIUS_HILL = qgisprocess:::qgis_default_value(),
  THRESHOLD = qgisprocess:::qgis_default_value(),
  METHOD = qgisprocess:::qgis_default_value(),
  ...,
  .complete_output = .complete_output_option(),
  .quiet = .quiet_option(),
  .messages = .message_option()
)

Arguments

DEM

raster - Elevation. Path to a raster layer.

VALLEY

rasterDestination - Valley Depth. Path for new raster layer.

HILL

rasterDestination - Hill Height. Path for new raster layer.

VALLEY_IDX

rasterDestination - Valley Index. Path for new raster layer.

HILL_IDX

rasterDestination - Hill Index. Path for new raster layer.

SLOPE_IDX

rasterDestination - Hillslope Index. Path for new raster layer.

RADIUS_VALLEY

number - Valley Radius. 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.

RADIUS_HILL

number - Hill Radius. 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.

THRESHOLD

number - Elevation Threshold. 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.

METHOD

enum of ("(0) default", "(1) alternative") - Slope Index. Number of selected option, e.g. '1'. Comma separated list of options, e.g. '1,3'.

...

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

  • HILL - outputRaster - Hill Height

  • HILL_IDX - outputRaster - Hill Index

  • SLOPE_IDX - outputRaster - Hillslope Index

  • VALLEY - outputRaster - Valley Depth

  • VALLEY_IDX - outputRaster - Valley Index