R/gdal_slope.R

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

##' QGIS Algorithm provided by GDAL Slope (gdal:slope). ---------------- Arguments ----------------  INPUT: Input layer 	Argument type:	raster 	Acceptable values: 		- Path to a raster layer BAND: Band number 	Default value:	1 	Argument type:	band 	Acceptable values: 		- Integer value representing an existing raster band number SCALE: Ratio of vertical units to horizontal 	Default value:	1 	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 AS_PERCENT: Slope expressed as percent instead of degrees 	Default value:	false 	Argument type:	boolean 	Acceptable values: 		- 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 COMPUTE_EDGES: Compute edges 	Default value:	false 	Argument type:	boolean 	Acceptable values: 		- 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 ZEVENBERGEN: Use Zevenbergen&Thorne formula instead of the Horn's one 	Default value:	false 	Argument type:	boolean 	Acceptable values: 		- 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 OPTIONS: Additional creation options (optional) 	Default value:	 	Argument type:	string 	Acceptable values: 		- 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 EXTRA: Additional command-line parameters (optional) 	Argument type:	string 	Acceptable values: 		- 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: Slope 	Argument type:	rasterDestination 	Acceptable values: 		- Path for new raster layer
##'
##' @title QGIS algorithm - Slope
##'
##' @param INPUT `raster` - Input layer. Path to a raster layer.
##' @param BAND `band` - Band number. Integer value representing an existing raster band number.
##' @param SCALE `number` - Ratio of vertical units to horizontal. 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.
##' @param AS_PERCENT `boolean` - Slope expressed as percent instead of degrees. 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.
##' @param COMPUTE_EDGES `boolean` - Compute edges. 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.
##' @param ZEVENBERGEN `boolean` - Use Zevenbergen&Thorne formula instead of the Horn's one. 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.
##' @param OPTIONS `string` - Additional creation options. 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.
##' @param EXTRA `string` - Additional command-line parameters. 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.
##' @param OUTPUT `rasterDestination` - Slope. Path for new raster layer.
##' @param ... further parameters passed to `qgisprocess::qgis_run_algorithm()`
##' @param .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`.
##' @param .quiet logical specifying if parameter `.quiet` for `qgisprocess::qgis_run_algorithm()` Default value is `TRUE`.
##' @param .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 - outputRaster - Slope
##'
##'
##' @export
##' @md
##' @importFrom qgisprocess qgis_run_algorithm

gdal_slope <- function(INPUT = qgisprocess:::qgis_default_value(), BAND = qgisprocess:::qgis_default_value(), SCALE = qgisprocess:::qgis_default_value(), AS_PERCENT = qgisprocess:::qgis_default_value(), COMPUTE_EDGES = qgisprocess:::qgis_default_value(), ZEVENBERGEN = qgisprocess:::qgis_default_value(), OPTIONS = qgisprocess:::qgis_default_value(), EXTRA = qgisprocess:::qgis_default_value(), OUTPUT = qgisprocess:::qgis_default_value(),..., .complete_output = .complete_output_option(), .quiet = .quiet_option(), .messages = .message_option()) {

  check_algorithm_necessities("gdal:slope")

  if (.messages){
    output <- qgisprocess::qgis_run_algorithm("gdal:slope", `INPUT` = INPUT, `BAND` = BAND, `SCALE` = SCALE, `AS_PERCENT` = AS_PERCENT, `COMPUTE_EDGES` = COMPUTE_EDGES, `ZEVENBERGEN` = ZEVENBERGEN, `OPTIONS` = OPTIONS, `EXTRA` = EXTRA, `OUTPUT` = OUTPUT,..., .quiet = .quiet)
  } else {
    suppressMessages(
      output <- qgisprocess::qgis_run_algorithm("gdal:slope", `INPUT` = INPUT, `BAND` = BAND, `SCALE` = SCALE, `AS_PERCENT` = AS_PERCENT, `COMPUTE_EDGES` = COMPUTE_EDGES, `ZEVENBERGEN` = ZEVENBERGEN, `OPTIONS` = OPTIONS, `EXTRA` = EXTRA, `OUTPUT` = OUTPUT,..., .quiet = .quiet)
      )
  }

  if (.complete_output) {
    return(output)
  }
  else{
    qgisprocess::qgis_extract_output(output, "OUTPUT")
  }
}