R/envs_worldclim.R

In wallace: A Modular Platform for Reproducible Modeling of Species Niches and Distributions

#' @title envs_worldclim Obtain WorldClim variables
#' @description download WorldClim variables. See www.worldclim.com.
#'
#' @details This function is called by the module envs to download
#'   WorldClim variables from www.worldclim.com. The variables to be downloaded
#'   are selected by the user with bcSel and the resolution with bcRes. It
#'   returns either a rasterStack or rasterBrick of selected variables with
#'   appropriate names for further analyses.
#'
#' @param bcRes numeric. Resolution of the climatic layers. Currently
#'   available resolutions are 0.5, 2.5 and 10.
#' @param bcSel character. Vector with bionames to be selected.
#' @param mapCntr numeric. Vector with longitude and latitude for a tile.
#'   Required for bcRes 0.5, for other resolutions world data will be downloaded.
#' @param doBrick logical. Converts downloaded rasters to brick for faster
#'   processing.
#' @param logger Stores all notification messages to be displayed in the
#'   Log Window of Wallace GUI. Insert the logger reactive list here for
#'   running in shiny, otherwise leave the default NULL.
#'
#' @examples
#' \dontrun{
#' bcRes <- 10 # (10 arcmin)
#' envar <- c('bio05', 'bio06', 'bio13', 'bio14')
#' arcmin10 <- envs_worldclim(bcRes, bcSel = envar)
#' }
#'
#' @return A rasterStack or a rasterBrick (if doBrick=TRUE) of downloaded
#'  worldclim rasters at the requested resolution.
#'
#' @author Jamie Kass <jamie.m.kass@@gmail.com>
#' @author Gonzalo E. Pinilla-Buitrago <gepinillab@@gmail.com>
#'
#' @seealso \code{\link[raster]{getData}}
#'
#' @export

envs_worldclim <- function(bcRes, bcSel, mapCntr, doBrick = FALSE,
                           logger = NULL) {
  if(bcRes == '') {
    logger %>% writeLog(type = 'error', 'Select a raster resolution.')
    return()
  }

  smartProgress(logger, message = "Retrieving WorldClim data...", {
      wcbc <- raster::getData(name = "worldclim", var = "bio", res = bcRes,
                              lon = mapCntr[1], lat = mapCntr[2])
      # change names if bio01 is bio1, and so forth
      if (bcRes == 0.5) {
        names(wcbc) <- gsub("_.*", "", names(wcbc))
      }
      i <- grep('bio[0-9]$', names(wcbc))
      editNames <- paste('bio', sapply(strsplit(names(wcbc)[i], 'bio'),
                                       function(x) x[2]), sep = '0')
      names(wcbc)[i] <- editNames

      wcbc <- wcbc[[bcSel]]
  })

  # convert to brick for faster processing
  if(doBrick == TRUE) {
    smartProgress(logger,
                         message = "Converting to RasterBrick for faster processing...", {
      wcbc <- raster::brick(wcbc)
    })
  }

  logger %>% writeLog("WorldClim bioclimatic variables ",
                      paste(names(wcbc), collapse = ", "), " at ",
                      bcRes, " arcmin resolution.")
  return(wcbc)
}