R/gt_compareRaster.R

In jeffreyhanson/geotrellis: geotrellis: spatial data analysis using geotrellis

#' @include gt_RasterLayer.R
NULL

#' Compare geotrellis raster objects
#'
#' Evaluate whether two \code{\link{gt_RasterLayer}} objects have the same
#' extent, number of rows and columns, projection, and resolution
#' (or a subset of these comparisons).
#' @param x \code{\link{gt_RasterLayer}}.
#' @param y \code{\link{gt_RasterLayer}}.
#' @param extent \code{logical} should the objects' extent be compared?
#' Defaults to \code{TRUE}.
#' @param rowcol \code{logical} should the objects' dimensionality be compared?
#' Defaults to \code{TRUE}.
#' @param crs \code{logical} should the objects' coordinate refernece systems
#' be compared?
#' @param res \code{logical} should the objects' resolution be compared? 
#' Defaults to \code{TRUE}.
#' @param tolerance \code{numeric} This sets the difference between values
#' that is permissible for them to be considered equal. Defaults to 0.1.
#' @param stopiffalse \code{logical} should an error be thrown if one or
#' more conditions are not met?
#' @param showwarning \code{logical} should a warning be thrown if one or
#' more conditions are not met?
#' @details This function is similar to \code{\link[raster]{compareRaster}}
#' except that is is less rigorous.
#' @return \code{logical} are all tested parameters the same?
#' @examples
#' \dontrun{
#' g <- gt_raster(raster::raster(matrix(runif(9), ncol=3),
#'                               crs=sp::CRS('+init=epsg:4326'),
#'                               xmn=0, xmx=3, ymn=2, ymx=10))
#' g2 <- gt_raster(raster::raster(matrix(runif(9), ncol=3),
#'                               crs=sp::CRS('+init=epsg:3395'),
#'                               xmn=0, xmx=3, ymn=2, ymx=10))
#' g3 <- gt_raster(raster::raster(matrix(runif(9), ncol=3),
#'                               crs=sp::CRS('+init=epsg:4326'),
#'                               xmn=10, xmx=13, ymn=12, ymx=20))
#' gt_compareRaster(g, g) # same properties
#' gt_compareRaster(g, g2, stopiffalse=FALSE) # different crs
#' gt_compareRaster(g, g2, stopiffalse=FALSE) # different extent
#' }
#' @export
gt_compareRaster <- function(x, y, extent=TRUE, rowcol=TRUE, crs=TRUE, res=TRUE,
                             tolerance=0.1, stopiffalse=TRUE, showwarning=FALSE) {
  assertthat::assert_that(
    assertthat::is.flag(extent),
    assertthat::is.flag(rowcol),
    assertthat::is.flag(crs),
    assertthat::is.flag(res),
    assertthat::is.flag(stopiffalse),
    assertthat::is.flag(showwarning),
    assertthat::is.number(tolerance),
    tolerance > 0
  )
  x$compare(y, extent, rowcol, crs, res, tolerance, stopiffalse, showwarning)
}