R/qgis_randomextractwithinsubsets.R

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

##' QGIS Algorithm provided by QGIS Random extract within subsets (qgis:randomextractwithinsubsets). This algorithm takes a vector layer and generates a new one that contains only a subset of the features in the input layer. The subset is defined randomly, using a percentage or count value to define the total number of features in the subset. The percentage/count value is not applied to the whole layer, but instead to each category. Categories are defined according to a given attribute, which is also specified as an input parameter for the algorithm.
##'
##' @title QGIS algorithm - Random extract within subsets
##'
##' @param INPUT `source` - Input layer. Path to a vector layer.
##' @param FIELD `field` - ID field. The name of an existing field. ; delimited list of existing field names.
##' @param METHOD `enum`  of `("Number of selected features", "Percentage of selected features")` - Method. Number of selected option, e.g. '1'. Comma separated list of options, e.g. '1,3'.
##' @param NUMBER `number` - Number\code{/}percentage of selected features. 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 `sink` - Extracted (random stratified). Path for new vector 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 - outputVector - Extracted (random stratified)
##'
##'
##' @export
##' @md
##' @importFrom qgisprocess qgis_run_algorithm

qgis_randomextractwithinsubsets <- function(INPUT = qgisprocess:::qgis_default_value(), FIELD = qgisprocess:::qgis_default_value(), METHOD = qgisprocess:::qgis_default_value(), NUMBER = qgisprocess:::qgis_default_value(), OUTPUT = qgisprocess:::qgis_default_value(),..., .complete_output = .complete_output_option(), .quiet = .quiet_option(), .messages = .message_option()) {

  check_algorithm_necessities("qgis:randomextractwithinsubsets")

  if (.messages){
    output <- qgisprocess::qgis_run_algorithm("qgis:randomextractwithinsubsets", `INPUT` = INPUT, `FIELD` = FIELD, `METHOD` = METHOD, `NUMBER` = NUMBER, `OUTPUT` = OUTPUT,..., .quiet = .quiet)
  } else {
    suppressMessages(
      output <- qgisprocess::qgis_run_algorithm("qgis:randomextractwithinsubsets", `INPUT` = INPUT, `FIELD` = FIELD, `METHOD` = METHOD, `NUMBER` = NUMBER, `OUTPUT` = OUTPUT,..., .quiet = .quiet)
      )
  }

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