R/upForcing.R

In DWBmodelUN: Dynamic Water Balance a Hydrological Model

#' @name 
#' upForcing
#'
#' @title
#' Upload Forcings
#'
#' @description This function loads the precipitation and evapotranspiration estimates that will be used
#' to run or force the DWB model (\code{\link{DWBCalculator}}). If files are in raster format, it saves a variable 
#' cointaining the inputs in table format.
#'
#' @param path_p is a character string that specifies the directory where the precipitation rasters or
#' the csv file are stored. The csv file must have nrows = N° of cells and ncol= N° of time steps.
#' @param path_pet is a character string that specifies the location of the potential evapotranspiration rasters or
#' the csv file are stored. The csv file must have nrows= N° of cells and ncol= N° of time steps.
#' @param file_type Character string that specifies the forcing file formats, it should be "raster" or "csv",
#' the default value is "raster".
#' @param format Character string that specifies the format file of the Rasters, possible values are "GTiff"
#' and "NetCDF". Default value is "GTiff".
#' 
#' @details The character strings that control the location of the forcing files are as default "\emph{./precip/}"
#' and "\emph{./pet/}" for precipitation and potential evapotranspiration, but can be change to other directories.
#' However, if one's intention is to upload them from NetCDF files, the \bold{strings must be completely changed} to
#' a complete path that includes the name and extension of the file.
#'
#' @return a list containing the two objects (P and PET).
#' 
#' @author
#' Nicolas Duque Gardeazabal <nduqueg@unal.edu.co> \cr
#' Pedro Felipe Arboleda <pfarboledao@unal.edu.co> \cr
#' Carolina Vega Viviescas <cvegav@unal.edu.co> \cr
#' David Zamora <dazamoraa@unal.edu.co> \cr
#' 
#' Water Resources Engineering Research Group - GIREH
#' Universidad Nacional de Colombia - sede Bogota
#' 
#' @export
#' 
#' 
upForcing <- function(path_p = tempdir(), path_pet = tempdir(), file_type = "raster", format = "GTiff"){
  
  if (!exists("path_pet")){
    stop("Not filepath to read evapotranspiration data")
  } else if (!exists("path_p")){
    stop("Not filepath to read precipitation data")
  } 
  if (file_type == "raster"){
    # ---- identify raster format and loading----
    if (format == "GTiff"){
      
      if( length(list.files(path_pet, pattern = ".tif")) == 0 | length( list.files(path_p, pattern = ".tif")) == 0){
        stop("Not avaliable data of precipitation or evapotranspiration")
      }
      pet_files <- list.files(path_pet)
      pet <- raster::stack(paste(path_pet, pet_files, sep = ""))
      p_files <- list.files(path_p)
      p <- raster::stack(paste(path_p, p_files, sep = ""))
    } else if(format == "NCDF"){
      if( length( list.files(path_pet, pattern = ".nc")) == 0 | length( list.files(path_p, pattern = ".nc")) == 0){
        stop("Not avaliable data of precipitation or evapotranspiration")
      }
      pet <- raster::brick(path_pet)
      p <- raster::brick(path_p)
    }
    # ---- transformation to dataframes ----
    p_v <- raster::rasterToPoints(p)
    pet_v <- raster::rasterToPoints(pet)
    } else {  # load forcings in csv files
    pet_files <- list.files(path_pet)
    p_files <- list.files(path_p)
    p_v <- read.csv(paste(path_p, p_files,sep = ""))
    pet_v <- read.csv(paste(path_pet, pet_files,sep = ""))
  }
  meteo <- list(PET = pet_v, Prec = p_v)
  return(meteo)
}