R/grass_r_contour.R

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

##' QGIS Algorithm provided by GRASS r.contour (grass:r.contour). Produces a vector map of specified contours from a raster map.
##'
##' @title QGIS algorithm - r.contour
##'
##' @param input `raster` - Input raster. Path to a raster layer.
##' @param step `number` - Increment between contour levels. 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 levels `string` - List of contour levels. 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 minlevel `number` - Minimum contour level. 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 maxlevel `number` - Maximum contour level. 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 cut `number` - Minimum number of points for a contour line (0 - no limit). 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 output `vectorDestination` - Contours. Path for new vector layer.
##' @param GRASS_REGION_PARAMETER `extent` - GRASS GIS region extent. A comma delimited string of x min, x max, y min, y max. E.g. '4,10,101,105'. Path to a layer. The extent of the layer is used..
##' @param GRASS_REGION_CELLSIZE_PARAMETER `number` - GRASS GIS region cellsize (leave 0 for default). 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 GRASS_OUTPUT_TYPE_PARAMETER `enum`  of `("auto", "point", "line", "area")` - v.out.ogr output type. Number of selected option, e.g. '1'. Comma separated list of options, e.g. '1,3'.
##' @param GRASS_VECTOR_DSCO `string` - v.out.ogr output data source options (dsco). 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 GRASS_VECTOR_LCO `string` - v.out.ogr output layer options (lco). 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 GRASS_VECTOR_EXPORT_NOCAT `boolean` - Also export features without category (not labeled). Otherwise only features with category are exported. 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 ... 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 - outputVector - Contours
##'
##'
##' @export
##' @md
##' @importFrom qgisprocess qgis_run_algorithm

grass_r_contour <- function(input = qgisprocess:::qgis_default_value(), step = qgisprocess:::qgis_default_value(), levels = qgisprocess:::qgis_default_value(), minlevel = qgisprocess:::qgis_default_value(), maxlevel = qgisprocess:::qgis_default_value(), cut = qgisprocess:::qgis_default_value(), output = qgisprocess:::qgis_default_value(), GRASS_REGION_PARAMETER = qgisprocess:::qgis_default_value(), GRASS_REGION_CELLSIZE_PARAMETER = qgisprocess:::qgis_default_value(), GRASS_OUTPUT_TYPE_PARAMETER = qgisprocess:::qgis_default_value(), GRASS_VECTOR_DSCO = qgisprocess:::qgis_default_value(), GRASS_VECTOR_LCO = qgisprocess:::qgis_default_value(), GRASS_VECTOR_EXPORT_NOCAT = qgisprocess:::qgis_default_value(),..., .complete_output = .complete_output_option(), .quiet = .quiet_option(), .messages = .message_option()) {

  check_algorithm_necessities("grass:r.contour")

  if (.messages){
    output <- qgisprocess::qgis_run_algorithm("grass:r.contour", `input` = input, `step` = step, `levels` = levels, `minlevel` = minlevel, `maxlevel` = maxlevel, `cut` = cut, `output` = output, `GRASS_REGION_PARAMETER` = GRASS_REGION_PARAMETER, `GRASS_REGION_CELLSIZE_PARAMETER` = GRASS_REGION_CELLSIZE_PARAMETER, `GRASS_OUTPUT_TYPE_PARAMETER` = GRASS_OUTPUT_TYPE_PARAMETER, `GRASS_VECTOR_DSCO` = GRASS_VECTOR_DSCO, `GRASS_VECTOR_LCO` = GRASS_VECTOR_LCO, `GRASS_VECTOR_EXPORT_NOCAT` = GRASS_VECTOR_EXPORT_NOCAT,..., .quiet = .quiet)
  } else {
    suppressMessages(
      output <- qgisprocess::qgis_run_algorithm("grass:r.contour", `input` = input, `step` = step, `levels` = levels, `minlevel` = minlevel, `maxlevel` = maxlevel, `cut` = cut, `output` = output, `GRASS_REGION_PARAMETER` = GRASS_REGION_PARAMETER, `GRASS_REGION_CELLSIZE_PARAMETER` = GRASS_REGION_CELLSIZE_PARAMETER, `GRASS_OUTPUT_TYPE_PARAMETER` = GRASS_OUTPUT_TYPE_PARAMETER, `GRASS_VECTOR_DSCO` = GRASS_VECTOR_DSCO, `GRASS_VECTOR_LCO` = GRASS_VECTOR_LCO, `GRASS_VECTOR_EXPORT_NOCAT` = GRASS_VECTOR_EXPORT_NOCAT,..., .quiet = .quiet)
      )
  }

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