R/Coord_comparison.R

In dazamora/DWBmodelUN: Dynamic Water Balance a Hydrological Model

#' @name 
#' Coord_comparison
#' 
#' @title
#' Raster coordinates comparison
#' 
#' @description 
#' This function compares three characteristics from two rasters:
#' coordinates, resolution, and number of layers (if the rasters have more than one) 
#' from two different rasters stacks, and let to know if they are using the same geographical information,
#' or if a new set-up should be done.
#' 
#' @param r1 raster or data frame. If it is a data frame, it should contain in the first two columns, the X, Y 
#' coordinates for every point, in GEOGRAPHIC COORDINATES, the third column and so on should have the variable values,
#' and optionally, the header should have the date, using the format \code{\%m/\%Y}.
#' @param r2 raster or data frame. If it is a data frame, it should contain in the first two columns, the X, Y 
#' coordinates for every point, in GEOGRAPHIC COORDINATES, the third column and so on should have the variable values,
#' and optionally, the header should have the date, using the format \code{\%m/\%Y}.
#'
#' @return It prints on console whether the two rasters are on the same coordinates or not, and return
#' a boolean, TRUE if the rasters are on the same coordinates, and FALSE if not.
#' 
#' @export
#' 
#' @author 
#' Pedro Felipe Arboleda Obando <pfarboledao@unal.edu.co>  \cr
#' Nicolas Duque Gardeazabal <nduqueg@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
#' 
#' @examples
#' data(P_sogamoso, PET_sogamoso)
#' Coord_comparison(P_sogamoso, PET_sogamoso)
#' 
Coord_comparison <- function(r1, r2){
  #Verify if r1 is data frame, if it is, convert to raster
  if(is.data.frame(r1)) {
    message("First data file is a data frame - Converting to raster")
    rummy <- raster::rasterFromXYZ(r1[ ,1:3])
    a1 <- r1
    r1 <- rummy
  }
  
  #Verify if r2 is data frame, if it is, convert to raster
  if(is.data.frame(r2)) {
    message("Second data file is a data frame - Converting to raster")
    rummy <- raster::rasterFromXYZ(r2[ ,1:3])
    a2 <- r2
    r2 <- rummy
  }
  
  # If the two inputs are data frames, the dates in the headers are compared
  # Careful!! The model will keep running even if the two headers does not match, but
  # there will be a warning
  # This code also compares number of columns. If the first date match, and the number of columns match
  # the code assumes that the final data match too
  if(is.data.frame(a2) & is.data.frame(a1)){
    message("Two data frames - Comparing headers")
    d1 <- colnames(a1)[-(1:2)]
    d2 <- colnames(a2)[-(1:2)]
    if(d1[1] == d2[1]) {
      message("First date matches")
      if(d1[length(d1)] == d2[length(d2)]){
        message("First date and final date match")
      }else{
        warning("First date matches, but final date does not match - Please verify")
      }
    }else{
      message("First date does not match according to the header")
      warning("The model will run, but WARNING - Please verify dates")
    }
  }
  ## Rasters are compared in extent, number of layers, and number of row - columns
  ## If those characteristics match, it is said the rasters use the same cell locations.
  er1 <- raster::extent(r1)
  er2 <- raster::extent(r2)
  if(er1 == er2){
    message("Extent verified")
    if(raster::res(r1)[1] == raster::res(r2)[1] & raster::res(r1)[2] == raster::res(r2)[2]){
      message("Resolution verified")
      if(raster::nlayers(r1) > 1 | raster::nlayers(r2) > 1){
        if(raster::nlayers(r1) == raster::nlayers(r2)){
          message("Number of layers verified")
          return(TRUE)
        }else{
          warning("Please verify number of layers in raster")
          return(FALSE)
        }
      }else{return(TRUE)}
      
    }else{
      warning("Please verify raster resolution")
      return(FALSE)
    }
  }else{
    warning("Please verify raster extent")
  }
}