R/extract_shape_postprob.R

In MelodyPremaillon/valwoe: Statistical validation of susceptibility maps builted with woe method

#' @title build a dataframe of postprob value for each point
#' @author Melody Premaillon
#'
#' @param path folder path where raster is saved
#' @param name_shape name of point shapefile
#' @param name_rast_postprob name of susceptibility raster
#'
#' @description This function takes two files : susceptibility raster and a point shapefile (can be trainning/valid or complete). One read, raster values are extracted from each point location. Finaly a df is build with unique postprob values of points set and their count.
#'
#' @return a data frame of unique postprob values and count of points
#' @export
#'
#' @import raster
#' @import rgdal
#' @import dplyr
#'

extract_shape_postprob <- function(path, name_shape, name_rast_postprob){

  rastpp <- raster(paste(path, "/", name_rast_postprob, ".tif", sep=""))
  postprob_shape <- readOGR(paste(path, "/", name_shape, ".shp", sep=""))

  shape_df <- data.frame(POST_PROB = raster::extract(rastpp, postprob_shape))

  shape_df <- shape_df %>%
    filter(!is.na(POST_PROB)) %>%
    group_by(POST_PROB) %>%
    summarise(POINTS = n())

  return(shape_df)
}