R/penvs_userBgExtent.R

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

#' @title penvs_userBgExtent: user provided background extent
#' @description This function generates a background area according to a user
#'   provided polygon and buffer.
#'
#' @details
#' This function is used in the select study region component. Here, the user
#'   provides either a shapefile or a csv with vertex coordinates with the
#'   desired shape for the background extent, the user may include a buffer to
#'   the given polygon. The buffered polygon must include all occurrences
#'   (occs) or function will return an error. The function returns a
#'   SpatialPolygons object of the desired extent (+ buffer).
#'
#' @param bgShp_path path to the user provided shapefile or csv with vertex
#'   coordinates.
#' @param bgShp_name name of the user provided shapefile or csv with vertex
#'   coordinates.
#' @param userBgBuf buffer to be used in creating the background extent must
#'   be >= 0.
#' @param occs data frame of cleaned or processed occurrences obtained from
#'   components occs: Obtain occurrence data or, poccs: Process occurrence data.
#' @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.
#' @param spN Species name.
#' @examples
#' occs <- read.csv(system.file("extdata/Bassaricyon_neblina.csv",
#'                  package = "wallace"))[, 2:3]
#' occs$occID <- 1:nrow(occs)
#' pathShp <- list.files(system.file("extdata/shp", package = "wallace"),
#'                       full.names = TRUE)
#' nameShp <- list.files(system.file("extdata/shp", package = "wallace"),
#'                       full.names = FALSE)
#' userBgbf <- penvs_userBgExtent(bgShp_path = pathShp, bgShp_name = nameShp,
#'                                userBgBuf = 0.2, occs = occs)
#'
#' @return This function returns a SpatialPolygons object with the user
#'   provided shape (+ a buffer if userBgBuf >0). The polygon will be at least
#'   large enough to contain all occurrences.
#' @author Jamie Kass <jamie.m.kass@@gmail.com>
#' @author Gonzalo E. Pinilla-Buitrago <gepinillab@@gmail.com>
#' @author Andrea Paz <paz.andreita@@gmail.com>
# @note

#' @seealso \code{\link{penvs_drawBgExtent}}, \code{\link{penvs_bgExtent}},
#'   \code{\link{penvs_bgMask}} , \code{\link{penvs_bgSample}}
#' @export

penvs_userBgExtent <- function(bgShp_path, bgShp_name, userBgBuf, occs,
                               logger = NULL, spN = NULL) {
    pathdir <- dirname(bgShp_path)
    pathfile <- basename(bgShp_path)
    # get extensions of all input files
    exts <- sapply(strsplit(bgShp_name, '\\.'), FUN = function(x) x[2])
    if (length(exts) == 1 & exts[1] == 'csv') {
      f <- utils::read.csv(bgShp_path, header = TRUE)
      bgExt <- sp::SpatialPolygons(list(sp::Polygons(list(sp::Polygon(f)), 1)))
    } else if ('shp' %in% exts) {
      if (length(exts) < 3) {
        logger %>%
          writeLog(type = 'error',
                   paste0('If entering a shapefile, please select all the ',
                          'following files: .shp, .shx, .dbf.'))
        return()
      }
      # get index of .shp
      i <- which(exts == 'shp')
      if (!file.exists(file.path(pathdir, bgShp_name)[i])) {
        file.rename(bgShp_path, file.path(pathdir, bgShp_name))
      }
      # read in shapefile and extract coords
      bgExt <- sf::st_read(file.path(pathdir, bgShp_name)[i])
      bgExt <- sf::as_Spatial(bgExt)
    } else {
      logger %>%
        writeLog(type = 'error',
                 paste0('Please enter either a CSV file of vertex coordinates ',
                        'or shapefile (.shp, .shx, .dbf).'))
      return()
    }

    if (userBgBuf >= 0) {
      bgExt <- sf::st_as_sf(bgExt)
      bgExt <- sf::st_buffer(bgExt, dist = userBgBuf)
      bgExt <- sf::as_Spatial(bgExt)
    } else {
      bgExt <- sf::st_as_sf(bgExt)
      bgExt <- sf::st_buffer(bgExt, dist = userBgBuf)
      bgExt <- sf::as_Spatial(bgExt)
    }

    ### Points outside polygon

    occs.xy <- occs[c('longitude', 'latitude')]
    # make spatial pts object of original occs and preserve origID
    pts <- sp::SpatialPointsDataFrame(occs.xy, data = occs['occID'])
    intersecto <- sp::over(pts, bgExt)
    ptRem <- ifelse(all(!is.na(intersecto)), 0,
                    as.numeric(which(is.na(intersecto))))
    if (ptRem == 0) {
      if (userBgBuf > 0) {
        logger %>% writeLog(
          hlSpp(spN),
          'Study extent user-defined polygon buffered by ', userBgBuf,
          ' degrees.')
      } else {
        logger %>% writeLog(
          hlSpp(spN), "Study extent: user-defined polygon.")
      }
      return(bgExt)
    } else if (ptRem > 0) {
      logger %>%
        writeLog(type = 'error', hlSpp(spN),
                 "The polygon did not include all localities. ",
                 "You can remove localities in Process Occs component")
      return()
    }
}