#'Interpolate arrays with longitude and latitude dimensions using CDO #' #'This function takes as inputs a multidimensional array (optional), a vector #'or matrix of longitudes, a vector or matrix of latitudes, a destination grid #'specification, and the name of a method to be used to interpolate (one of #'those available in the 'remap' utility in CDO). The interpolated array is #'returned (if provided) together with the new longitudes and latitudes.\cr\cr #'\code{CDORemap()} permutes by default the dimensions of the input array (if #'needed), splits it in chunks (CDO can work with data arrays of up to 4 #'dimensions), generates a file with the data of each chunk, interpolates it #'with CDO, reads it back into R and merges it into a result array. If no #'input array is provided, the longitude and latitude vectors will be #'transformed only. If the array is already on the desired destination grid, #'no transformation is performed (this behvaiour works only for lonlat and #'gaussian grids). \cr\cr #'Any metadata attached to the input data array, longitudes or latitudes will #'be preserved or accordingly modified. #' #'@param data_array Multidimensional numeric array to be interpolated. If #' provided, it must have at least a longitude and a latitude dimensions, #' identified by the array dimension names. The names for these dimensions #' must be one of the recognized by s2dverification (can be checked with #' \code{s2dv:::.KnownLonNames()} and \code{s2dv:::.KnownLatNames()}). #'@param lons Numeric vector or array of longitudes of the centers of the grid #' cells. Its size must match the size of the longitude/latitude dimensions #' of the input array. #'@param lats Numeric vector or array of latitudes of the centers of the grid #' cells. Its size must match the size of the longitude/latitude dimensions #' of the input array. #'@param grid Character string specifying either a name of a target grid #' (recognized by CDO; e.g.: 'r256x128', 't106grid') or a path to another #' NetCDF file which to read the target grid from (a single grid must be #' defined in such file). #'@param method Character string specifying an interpolation method #' (recognized by CDO; e.g.: 'con', 'bil', 'bic', 'dis', 'con2', 'laf', 'nn'). #' The following long names are also supported: 'conservative', 'bilinear', #' 'bicubic' and 'distance-weighted'. #'@param avoid_writes The step of permutation is needed when the input array #' has more than 3 dimensions and none of the longitude or latitude dimensions #' in the right-most position (CDO would not accept it without permuting #' previously). This step, executed by default when needed, can be avoided #' for the price of writing more intermediate files (whis usually is #' unconvenient) by setting the parameter \code{avoid_writes = TRUE}. #'@param crop Whether to crop the data after interpolation with #' 'cdo sellonlatbox' (TRUE) or to extend interpolated data to the whole #' world as CDO does by default (FALSE). The default value is TRUE.\cr #' \itemize{ #' \item{ #' If \code{crop = TRUE}, the longitude and latitude borders to be cropped #' at are taken as the limits of the cells at the borders (not the values #' of 'lons' and 'lats', which are perceived as cell centers), i.e., the #' resulting array will contain data that covers the same area as the input #' array. This is equivalent to specifying \code{crop = 'preserve'}, i.e., #' preserving area. Notice that the longitude range of returning array will #' follow the original data 'lons' instead of the target grid 'grid'. #' } #' \item{ #' If \code{crop = FALSE}, the returning array is not cropped, i.e., a #' global domain, and the longitude range will be the same as the target #' grid 'grid'. #' } #' \item{ #' If \code{crop = 'tight'}, the borders to be cropped at are taken as the #' minimum and maximum cell centers in 'lons' and 'lats', i.e., the area #' covered by the resulting array may be smaller if interpolating from a #' coarse grid to a fine grid. #' } #' \item{ #' The parameter 'crop' also accepts a numeric vector of customized borders #' to be cropped at:\cr #' c(western border, eastern border, southern border, northern border). #' } #' } #'@param force_remap Whether to force remapping, even if the input data array #' is already on the target grid. #'@param write_dir Path to the directory where to create the intermediate #' files for CDO to work. By default, the R session temporary directory is #' used (\code{tempdir()}). #' #'@return A list with the following components: #' \item{'data_array'}{The interpolated data array (if an input array #' is provided at all, NULL otherwise).} #' \item{'lons'}{The longitudes of the data on the destination grid.} #' \item{'lats'}{The latitudes of the data on the destination grid.} #'@examples #' \dontrun{ #'# Interpolating only vectors of longitudes and latitudes #'lon <- seq(0, 360 - 360/50, length.out = 50) #'lat <- seq(-90, 90, length.out = 25) #'tas2 <- CDORemap(NULL, lon, lat, 't170grid', 'bil', TRUE) #' #'# Minimal array interpolation #'tas <- array(1:50, dim = c(25, 50)) #'names(dim(tas)) <- c('lat', 'lon') #'lon <- seq(0, 360 - 360/50, length.out = 50) #'lat <- seq(-90, 90, length.out = 25) #'tas2 <- CDORemap(tas, lon, lat, 't170grid', 'bil', TRUE) #' #'# Metadata can be attached to the inputs. It will be preserved and #'# accordignly modified. #'tas <- array(1:50, dim = c(25, 50)) #'names(dim(tas)) <- c('lat', 'lon') #'lon <- seq(0, 360 - 360/50, length.out = 50) #'metadata <- list(lon = list(units = 'degrees_east')) #'attr(lon, 'variables') <- metadata #'lat <- seq(-90, 90, length.out = 25) #'metadata <- list(lat = list(units = 'degrees_north')) #'attr(lat, 'variables') <- metadata #'metadata <- list(tas = list(dim = list(lat = list(len = 25, #' vals = lat), #' lon = list(len = 50, #' vals = lon) #' ))) #'attr(tas, 'variables') <- metadata #'tas2 <- CDORemap(tas, lon, lat, 't170grid', 'bil', TRUE) #' #'# Arrays of any number of dimensions in any order can be provided. #'num_lats <- 25 #'num_lons <- 50 #'tas <- array(1:(10*num_lats*10*num_lons*10), #' dim = c(10, num_lats, 10, num_lons, 10)) #'names(dim(tas)) <- c('a', 'lat', 'b', 'lon', 'c') #'lon <- seq(0, 360 - 360/num_lons, length.out = num_lons) #'metadata <- list(lon = list(units = 'degrees_east')) #'attr(lon, 'variables') <- metadata #'lat <- seq(-90, 90, length.out = num_lats) #'metadata <- list(lat = list(units = 'degrees_north')) #'attr(lat, 'variables') <- metadata #'metadata <- list(tas = list(dim = list(a = list(), #' lat = list(len = num_lats, #' vals = lat), #' b = list(), #' lon = list(len = num_lons, #' vals = lon), #' c = list() #' ))) #'attr(tas, 'variables') <- metadata #'tas2 <- CDORemap(tas, lon, lat, 't17grid', 'bil', TRUE) #'# The step of permutation can be avoided but more intermediate file writes #'# will be performed. #'tas2 <- CDORemap(tas, lon, lat, 't17grid', 'bil', FALSE) #' #'# If the provided array has the longitude or latitude dimension in the #'# right-most position, the same number of file writes will be performed, #'# even if avoid_wrties = FALSE. #'num_lats <- 25 #'num_lons <- 50 #'tas <- array(1:(10*num_lats*10*num_lons*10), #' dim = c(10, num_lats, 10, num_lons)) #'names(dim(tas)) <- c('a', 'lat', 'b', 'lon') #'lon <- seq(0, 360 - 360/num_lons, length.out = num_lons) #'metadata <- list(lon = list(units = 'degrees_east')) #'attr(lon, 'variables') <- metadata #'lat <- seq(-90, 90, length.out = num_lats) #'metadata <- list(lat = list(units = 'degrees_north')) #'attr(lat, 'variables') <- metadata #'metadata <- list(tas = list(dim = list(a = list(), #' lat = list(len = num_lats, #' vals = lat), #' b = list(), #' lon = list(len = num_lons, #' vals = lon) #' ))) #'attr(tas, 'variables') <- metadata #'tas2 <- CDORemap(tas, lon, lat, 't17grid', 'bil', TRUE) #'tas2 <- CDORemap(tas, lon, lat, 't17grid', 'bil', FALSE) #' #'# An example of an interpolation from and onto a rectangular regular grid #'num_lats <- 25 #'num_lons <- 50 #'tas <- array(1:(1*num_lats*num_lons), dim = c(num_lats, num_lons)) #'names(dim(tas)) <- c('y', 'x') #'lon <- array(seq(0, 360 - 360/num_lons, length.out = num_lons), #' dim = c(num_lons, num_lats)) #'metadata <- list(lon = list(units = 'degrees_east')) #'names(dim(lon)) <- c('x', 'y') #'attr(lon, 'variables') <- metadata #'lat <- t(array(seq(-90, 90, length.out = num_lats), #' dim = c(num_lats, num_lons))) #'metadata <- list(lat = list(units = 'degrees_north')) #'names(dim(lat)) <- c('x', 'y') #'attr(lat, 'variables') <- metadata #'tas2 <- CDORemap(tas, lon, lat, 'r100x50', 'bil') #' #'# An example of an interpolation from an irregular grid onto a gaussian grid #'num_lats <- 25 #'num_lons <- 50 #'tas <- array(1:(10*num_lats*10*num_lons*10), #' dim = c(10, num_lats, 10, num_lons)) #'names(dim(tas)) <- c('a', 'j', 'b', 'i') #'lon <- array(seq(0, 360 - 360/num_lons, length.out = num_lons), #' dim = c(num_lons, num_lats)) #'metadata <- list(lon = list(units = 'degrees_east')) #'names(dim(lon)) <- c('i', 'j') #'attr(lon, 'variables') <- metadata #'lat <- t(array(seq(-90, 90, length.out = num_lats), #' dim = c(num_lats, num_lons))) #'metadata <- list(lat = list(units = 'degrees_north')) #'names(dim(lat)) <- c('i', 'j') #'attr(lat, 'variables') <- metadata #'tas2 <- CDORemap(tas, lon, lat, 't17grid', 'bil') #' #'# Again, the dimensions can be in any order #'num_lats <- 25 #'num_lons <- 50 #'tas <- array(1:(10*num_lats*10*num_lons), #' dim = c(10, num_lats, 10, num_lons)) #'names(dim(tas)) <- c('a', 'j', 'b', 'i') #'lon <- array(seq(0, 360 - 360/num_lons, length.out = num_lons), #' dim = c(num_lons, num_lats)) #'names(dim(lon)) <- c('i', 'j') #'lat <- t(array(seq(-90, 90, length.out = num_lats), #' dim = c(num_lats, num_lons))) #'names(dim(lat)) <- c('i', 'j') #'tas2 <- CDORemap(tas, lon, lat, 't17grid', 'bil') #'tas2 <- CDORemap(tas, lon, lat, 't17grid', 'bil', FALSE) #'# It is ossible to specify an external NetCDF file as target grid reference #'tas2 <- CDORemap(tas, lon, lat, 'external_file.nc', 'bil') #'} #'@import ncdf4 #'@importFrom easyNCDF ArrayToNc #'@importFrom stats lm predict setNames #'@export CDORemap <- function(data_array = NULL, lons, lats, grid, method, avoid_writes = TRUE, crop = TRUE, force_remap = FALSE, write_dir = tempdir()) { #, mask = NULL) { .isRegularVector <- function(x, tol = 0.1) { if (length(x) < 2) { #stop("The provided vector must be of length 2 or greater.") TRUE } else { spaces <- x[2:length(x)] - x[1:(length(x) - 1)] (sum(abs(spaces - mean(spaces)) > mean(spaces) / (1 / tol)) < 2) } } # Check parameters data_array, lons and lats. known_lon_names <- .KnownLonNames() known_lat_names <- .KnownLatNames() if (!is.numeric(lons) || !is.numeric(lats)) { stop("Expected numeric 'lons' and 'lats'.") } if (anyNA(lons > 0)) { stop("Found invalid values in 'lons'.") } if (anyNA(lats > 0)) { stop("Found invalid values in 'lats'.") } if (is.null(dim(lons))) { dim(lons) <- length(lons) } if (is.null(dim(lats))) { dim(lats) <- length(lats) } if (length(dim(lons)) > 2 || length(dim(lats)) > 2) { stop("'lons' and 'lats' can only have up to 2 dimensions.") } if (length(dim(lons)) != length(dim(lats))) { stop("'lons' and 'lats' must have the same number of dimensions.") } if (length(dim(lons)) == 2 && !all(dim(lons) == dim(lats))) { stop("'lons' and 'lats' must have the same dimension sizes.") } return_array <- TRUE if (is.null(data_array)) { return_array <- FALSE if (length(dim(lons)) == 1) { array_dims <- c(length(lats), length(lons)) new_lon_dim_name <- 'lon' new_lat_dim_name <- 'lat' if (!is.null(names(dim(lons)))) { if (any(known_lon_names %in% names(dim(lons)))) { new_lon_dim_name <- known_lon_names[which(known_lon_names %in% names(dim(lons)))[1]] } } if (!is.null(names(dim(lats)))) { if (any(known_lat_names %in% names(dim(lats)))) { new_lat_dim_name <- known_lat_names[which(known_lat_names %in% names(dim(lats)))[1]] } } names(array_dims) <- c(new_lat_dim_name, new_lon_dim_name) } else { # irregular array_dims <- dim(lons) if (is.null(names(array_dims))) { new_lon_dim_name <- 'i' new_lat_dim_name <- 'j' } } data_array <- array(as.numeric(NA), array_dims) } if (!(is.logical(data_array) || is.numeric(data_array)) || !is.array(data_array)) { stop("Parameter 'data_array' must be a numeric array.") } if (is.null(names(dim(data_array)))) { stop("Parameter 'data_array' must have named dimensions.") } lon_dim <- which(known_lon_names %in% names(dim(data_array))) if (length(lon_dim) < 1) { stop("Could not find a known longitude dimension name in the provided 'data_array'.") } if (length(lon_dim) > 1) { stop("Found more than one known longitude dimension names in the provided 'data_array'.") } lon_dim <- known_lon_names[lon_dim] lat_dim <- which(known_lat_names %in% names(dim(data_array))) if (length(lat_dim) < 1) { stop("Could not find a known latitude dimension name in the provided 'data_array'.") } if (length(lat_dim) > 1) { stop("Found more than one known latitude dimension name in the provided 'data_array'.") } lat_dim <- known_lat_names[lat_dim] if (is.null(names(dim(lons)))) { if (length(dim(lons)) == 1) { names(dim(lons)) <- lon_dim } else { stop("Parameter 'lons' must be provided with dimension names.") } } else { if (!(lon_dim %in% names(dim(lons)))) { stop("Parameter 'lon' must have the same longitude dimension name as the 'data_array'.") } if (length(dim(lons)) > 1 && !(lat_dim %in% names(dim(lons)))) { stop("Parameter 'lon' must have the same latitude dimension name as the 'data_array'.") } } if (is.null(names(dim(lats)))) { if (length(dim(lats)) == 1) { names(dim(lats)) <- lat_dim } else { stop("Parameter 'lats' must be provided with dimension names.") } } else { if (!(lat_dim %in% names(dim(lats)))) { stop("Parameter 'lat' must have the same latitude dimension name as the 'data_array'.") } if (length(dim(lats)) > 1 && !(lon_dim %in% names(dim(lats)))) { stop("Parameter 'lat' must have the same longitude dimension name as the 'data_array'.") } } lons_attr_bk <- attributes(lons) if (is.null(lons_attr_bk)) { lons_attr_bk <- list() } lats_attr_bk <- attributes(lats) if (is.null(lats_attr_bk)) { lats_attr_bk <- list() } if (length(attr(lons, 'variables')) == 0) { new_metadata <- list(list()) if (length(dim(lons)) == 1) { names(new_metadata) <- lon_dim } else { names(new_metadata) <- paste0(lon_dim, '_var') } attr(lons, 'variables') <- new_metadata } if (!('units' %in% names(attr(lons, 'variables')[[1]]))) { new_metadata <- attr(lons, 'variables') #names(new_metadata)[1] <- lon_dim new_metadata[[1]][['units']] <- 'degrees_east' attr(lons, 'variables') <- new_metadata } if (length(attr(lats, 'variables')) == 0) { new_metadata <- list(list()) if (length(dim(lats)) == 1) { names(new_metadata) <- lat_dim } else { names(new_metadata) <- paste0(lat_dim, '_var') } attr(lats, 'variables') <- new_metadata } if (!('units' %in% names(attr(lats, 'variables')[[1]]))) { new_metadata <- attr(lats, 'variables') #names(new_metadata)[1] <- lat_dim new_metadata[[1]][['units']] <- 'degrees_north' attr(lats, 'variables') <- new_metadata } # Check grid. if (!is.character(grid)) { stop("Parameter 'grid' must be a character string specifying a ", "target CDO grid, 'rXxY' or 'tRESgrid', or a path to another ", "NetCDF file.") } if (grepl('^r[0-9]{1,}x[0-9]{1,}$', grid)) { grid_type <- 'regular' grid_lons <- as.numeric(strsplit(strsplit(grid, 'x')[[1]][1], 'r')[[1]][2]) grid_lats <- as.numeric(strsplit(grid, 'x')[[1]][2]) } else if (grepl('^t[0-9]{1,}grid$', grid)) { grid_type <- 'gaussian' grid_t <- as.numeric(strsplit(strsplit(grid, 'grid')[[1]][1], 't')[[1]][2]) grid_size <- .t2nlatlon(grid_t) grid_lons <- grid_size[2] grid_lats <- grid_size[1] } else { grid_type <- 'custom' } # Check method. if (method %in% c('bil', 'bilinear')) { method <- 'bil' } else if (method %in% c('bic', 'bicubic')) { method <- 'bic' } else if (method %in% c('con', 'conservative')) { method <- 'con' } else if (method %in% c('dis', 'distance-weighted')) { method <- 'dis' } else if (method %in% 'nn') { method <- 'nn' } else if (method %in% 'laf') { method <- 'laf' } else if (method %in% 'con2') { method <- 'con2' } else { stop("Unsupported CDO remap method. Only 'bilinear', 'bicubic', 'conservative', 'distance-weighted', 'nn', 'laf', and 'con2' are supported.") } # Check avoid_writes if (!is.logical(avoid_writes)) { stop("Parameter 'avoid_writes' must be a logical value.") } # Check crop crop_tight <- FALSE if (is.character(crop)) { if (crop == 'tight') { crop_tight <- TRUE } else if (crop != 'preserve') { stop("Parameter 'crop' can only take the values 'tight' or 'preserve' if specified as a character string.") } crop <- TRUE } if (is.logical(crop)) { if (crop) { if (length(lons) == 1 || length(lats) == 1) { stop("CDORemap cannot remap if crop = TRUE and values for only one ", "longitude or one latitude are provided. Either a) provide ", "values for more than one longitude/latitude, b) explicitly ", "specify the crop limits in the parameter crop, or c) set ", "crop = FALSE.") } if (crop_tight) { lon_extremes <- c(min(lons), max(lons)) lat_extremes <- c(min(lats), max(lats)) } else { # Here we are trying to look for the extreme lons and lats in the data. # Not the centers of the extreme cells, but the borders of the extreme cells. ###--- if (length(dim(lons)) == 1) { tmp_lon <- lons } else { min_pos <- which(lons == min(lons), arr.ind = TRUE)[1, ] tmp_lon <- Subset(lons, lat_dim, min_pos[which(names(dim(lons)) == lat_dim)], drop = 'selected') } i <- 1:length(tmp_lon) degree <- min(3, length(i) - 1) lon_model <- lm(tmp_lon ~ poly(i, degree)) lon_extremes <- c(NA, NA) left_is_min <- FALSE right_is_max <- FALSE if (which.min(tmp_lon) == 1) { left_is_min <- TRUE prev_lon <- predict(lon_model, data.frame(i = 0)) first_lon_cell_width <- (tmp_lon[1] - prev_lon) # The signif is needed because cdo sellonlatbox crashes with too many digits lon_extremes[1] <- tmp_lon[1] - first_lon_cell_width / 2 } else { lon_extremes[1] <- min(tmp_lon) } if (which.max(tmp_lon) == length(tmp_lon)) { right_is_max <- TRUE next_lon <- predict(lon_model, data.frame(i = length(tmp_lon) + 1)) last_lon_cell_width <- (next_lon - tmp_lon[length(tmp_lon)]) lon_extremes[2] <- tmp_lon[length(tmp_lon)] + last_lon_cell_width / 2 } else { lon_extremes[2] <- max(tmp_lon) } # Adjust the crop window if possible in order to keep lons from 0 to 360 # or from -180 to 180 when the extremes of the cropped window are contiguous. if (right_is_max) { if (lon_extremes[1] < -180) { if (!((lon_extremes[2] < 180) && !((180 - lon_extremes[2]) <= last_lon_cell_width / 2))) { lon_extremes[1] <- -180 lon_extremes[2] <- 180 } } else if (lon_extremes[1] < 0) { if (!((lon_extremes[2] < 360) && !((360 - lon_extremes[2]) <= last_lon_cell_width / 2))) { lon_extremes[1] <- 0 lon_extremes[2] <- 360 } } } if (left_is_min) { if (lon_extremes[2] > 360) { if (!((lon_extremes[1] > 0) && !(lon_extremes[1] <= first_lon_cell_width / 2))) { lon_extremes[1] <- 0 lon_extremes[2] <- 360 } } else if (lon_extremes[2] > 180) { if (!((lon_extremes[1] > -180) && !((180 + lon_extremes[1]) <= first_lon_cell_width / 2))) { lon_extremes[1] <- -180 lon_extremes[2] <- 180 } } } ## lon_extremes <- signif(lon_extremes, 5) ## lon_extremes <- lon_extremes + 0.00001 ###--- if (length(dim(lats)) == 1) { tmp_lat <- lats } else { min_pos <- which(lats == min(lats), arr.ind = TRUE)[1, ] tmp_lat <- Subset(lats, lon_dim, min_pos[which(names(dim(lats)) == lon_dim)], drop = 'selected') } i <- 1:length(tmp_lat) degree <- min(3, length(i) - 1) lat_model <- lm(tmp_lat ~ poly(i, degree)) lat_extremes <- c(NA, NA) if (which.min(tmp_lat) == 1) { prev_lat <- predict(lat_model, data.frame(i = 0)) lat_extremes[1] <- tmp_lat[1] - (tmp_lat[1] - prev_lat) / 2 } else { lat_extremes[1] <- min(tmp_lat) } if (which.max(tmp_lat) == length(tmp_lat)) { next_lat <- predict(lat_model, data.frame(i = length(tmp_lat) + 1)) lat_extremes[2] <- tmp_lat[length(tmp_lat)] + (next_lat - tmp_lat[length(tmp_lat)]) / 2 } else { lat_extremes[2] <- max(tmp_lat) } ## lat_extremes <- signif(lat_extremes, 5) # Adjust crop window if (lat_extremes[1] < -90) { lat_extremes[1] <- -90 } else if (lat_extremes[1] > 90) { lat_extremes[1] <- 90 } if (lat_extremes[2] < -90) { lat_extremes[2] <- -90 } else if (lat_extremes[2] > 90) { lat_extremes[2] <- 90 } ###--- } } } else if (is.numeric(crop)) { if (length(crop) != 4) { stop("Paramrter 'crop' must be a logical value or a numeric vector of length 4: c(western border, eastern border, southern border, northern border.") } else { lon_extremes <- crop[1:2] lat_extremes <- crop[3:4] crop <- TRUE } } else { stop("Parameter 'crop' must be a logical value or a numeric vector.") } # Check force_remap if (!is.logical(force_remap)) { stop("Parameter 'force_remap' must be a logical value.") } # Check write_dir if (!is.character(write_dir)) { stop("Parameter 'write_dir' must be a character string.") } if (!dir.exists(write_dir)) { stop("Parameter 'write_dir' must point to an existing directory.") } # if (!is.null(mask)) { # if (!is.numeric(mask) || !is.array(mask)) { # stop("Parameter 'mask' must be a numeric array.") # } # if (length(dim(mask)) != 2) { # stop("Parameter 'mask' must have two dimensions.") # } # if (is.null(names(dim(mask)))) { # if (dim(data_array)[lat_dim] == dim(data_array)[lon_dim]) { # stop("Cannot disambiguate which is the longitude dimension of ", # "the provided 'mask'. Provide it with dimension names.") # } # names(dim(mask)) <- c('', '') # found_lon_dim <- which(dim(mask) == dim(data_array)[lon_dim]) # if (length(found_lon_dim) < 0) { # stop("The dimension sizes of the provided 'mask' do not match ", # "the spatial dimension sizes of the array to interpolate.") # } else { # names(dim(mask)[found_lon_dim]) <- lon_dim # } # found_lat_dim <- which(dim(mask) == dim(data_array)[lat_dim]) # if (length(found_lat_dim) < 0) { # stop("The dimension sizes of the provided 'mask' do not match ", # "the spatial dimension sizes of the array to interpolate.") # } else { # names(dim(mask)[found_lat_dim]) <- lat_dim # } # } # lon_position <- which(names(dim(data_array)) == lon_dim) # lat_position <- which(names(dim(data_array)) == lat_dim) # if (lon_position > lat_position) { # if (names(dim(mask))[1] == lon_dim) { # mask <- t(mask) # } # } else { # if (names(dim(mask))[1] == lat_dim) { # mask <- t(mask) # } # } # ## TODO: Apply mask!!! Preserve attributes # } # Check if interpolation can be skipped. interpolation_needed <- TRUE if (!force_remap) { if (!(grid_type == 'custom')) { if (length(lons) == grid_lons && length(lats) == grid_lats) { if (grid_type == 'regular') { if (.isRegularVector(lons) && .isRegularVector(lats)) { interpolation_needed <- FALSE } } else if (grid_type == 'gaussian') { # TODO: improve this check. Gaussian quadrature should be used. if (.isRegularVector(lons) && !.isRegularVector(lats)) { interpolation_needed <- FALSE } } } } } found_lons <- lons found_lats <- lats if (interpolation_needed) { if (nchar(Sys.which('cdo')[1]) < 1) { stop("CDO must be installed in order to use the .CDORemap.") } cdo_version <- as.numeric_version( strsplit(suppressWarnings(system2("cdo", args = '-V', stderr = TRUE))[[1]], ' ')[[1]][5] ) .warning(paste0("CDORemap: Using CDO version ", cdo_version, ".")) if ((cdo_version >= as.numeric_version('1.7.0')) && (method == 'con')) { method <- 'ycon' } # CDO takes arrays of 3 dimensions or 4 if one of them is unlimited. # The unlimited dimension can only be the left-most (right-most in R). # There are no restrictions for the dimension names or variable names. # The longitude and latitude are detected by their units. # There are no restrictions for the order of the limited dimensions. # The longitude/latitude variables and dimensions must have the same name. # The procedure consists in: # - take out the array metadata # - be aware of var dimension (replacing the dimension names would do). # - take arrays of 4 dimensions always if possible # - make the last dimension unlimited when saving to netcdf # - if the last dimension is lon or lat, either reorder the array and # then reorder back or iterate over the dimensions at the right # side of lon AND lat. # If the input array has more than 4 dimensions, it is needed to # run CDO on each sub-array of 4 dimensions because it can handle # only up to 4 dimensions. The shortest dimensions are chosen to # iterate over. is_irregular <- FALSE if (length(dim(lats)) > 1 && length(dim(lons)) > 1) { is_irregular <- TRUE } attribute_backup <- attributes(data_array) other_dims <- which(!(names(dim(data_array)) %in% c(lon_dim, lat_dim))) permutation <- NULL unlimited_dim <- NULL dims_to_iterate <- NULL total_slices <- 1 other_dims_per_chunk <- ifelse(is_irregular, 1, 2) # 4 (the maximum accepted by CDO) - 2 (lon, lat) = 2. if (length(other_dims) > 1 || (length(other_dims) > 0 && (is_irregular))) { # If lat/lon is the last dimension OR the largest other_dims is not the last one, # reorder the largest other dimension to the last as unlimited dim. if (!(length(dim(data_array)) %in% other_dims) | which.max(dim(data_array)[other_dims]) != length(other_dims)) { if (avoid_writes || is_irregular) { dims_mod <- dim(data_array) dims_mod[which(names(dim(data_array)) %in% c(lon_dim, lat_dim))] <- 0 dim_to_move <- which.max(dims_mod) permutation <- (1:length(dim(data_array)))[-dim_to_move] permutation <- c(permutation, dim_to_move) permutation_back <- sort(permutation, index.return = TRUE)$ix # dim_backup <- dim(data_array) data_array <- aperm(data_array, permutation) # dim(data_array) <- dim_backup[permutation] other_dims <- which(!(names(dim(data_array)) %in% c(lon_dim, lat_dim))) } else { # We allow only lon, lat and 1 more dimension per chunk, so # CDO has no restrictions in the order. other_dims_per_chunk <- 1 } } other_dims_ordered_by_size <- other_dims[sort(dim(data_array)[other_dims], index.return = TRUE)$ix] dims_to_iterate <- sort(head(other_dims_ordered_by_size, length(other_dims) - other_dims_per_chunk)) if (length(dims_to_iterate) == 0) { dims_to_iterate <- NULL } else { slices_to_iterate <- array(1:prod(dim(data_array)[dims_to_iterate]), dim(data_array)[dims_to_iterate]) total_slices <- prod(dim(slices_to_iterate)) } if ((other_dims_per_chunk > 1) || (other_dims_per_chunk > 0 && is_irregular)) { #NOTE: Why don't we use the second line here? In history, that line was never used. # The first line sort() can cause problems. If the largest other_dims is always # the last dim, tail(other_dims) is enough. unlimited_dim <- tail(sort(tail(other_dims_ordered_by_size, other_dims_per_chunk)), 1) #unlimited_dim <- tail(other_dims) } } result_array <- NULL lon_pos <- which(names(dim(data_array)) == lon_dim) lat_pos <- which(names(dim(data_array)) == lat_dim) dim_backup <- dim(data_array) attributes(data_array) <- NULL dim(data_array) <- dim_backup names(dim(data_array)) <- paste0('dim', 1:length(dim(data_array))) names(dim(data_array))[c(lon_pos, lat_pos)] <- c(lon_dim, lat_dim) if (!is.null(unlimited_dim)) { # This will make ArrayToNc create this dim as unlimited. names(dim(data_array))[unlimited_dim] <- 'time' # create time variable. The value is random since CDORemap() doesn't support time remapping now and we just want to avoid cdo warning time_attr <- array(c(1:dim(data_array)[unlimited_dim]), dim = c(dim(data_array)[unlimited_dim])) } if (length(dim(lons)) == 1) { names(dim(lons)) <- lon_dim } if (length(dim(lats)) == 1) { names(dim(lats)) <- lat_dim } if (length(dim(lons)) > 1) { lon_var_name <- paste0(lon_dim, '_var') } else { lon_var_name <- lon_dim } if (length(dim(lats)) > 1) { lat_var_name <- paste0(lat_dim, '_var') } else { lat_var_name <- lat_dim } if (is_irregular) { metadata <- list(list(coordinates = paste(lon_var_name, lat_var_name))) names(metadata) <- 'var' attr(data_array, 'variables') <- metadata } names(attr(lons, 'variables')) <- lon_var_name names(attr(lats, 'variables')) <- lat_var_name if (!is.null(attr(lons, 'variables')[[1]][['dim']])) { attr(lons, 'variables')[[1]][['dim']] <- NULL } if (!is.null(attr(lats, 'variables')[[1]][['dim']])) { attr(lats, 'variables')[[1]][['dim']] <- NULL } lons_lats_taken <- FALSE for (i in 1:total_slices) { tmp_file <- tempfile('R_CDORemap_', write_dir, fileext = '.nc') tmp_file2 <- tempfile('R_CDORemap_', write_dir, fileext = '.nc') if (!is.null(dims_to_iterate)) { slice_indices <- which(slices_to_iterate == i, arr.ind = TRUE) subset <- Subset(data_array, dims_to_iterate, as.list(slice_indices), drop = 'selected') # Fix issue 259, curvilinear grid, the order of the dimensions in slices and # coordinates needs to match if (is_irregular) { pos_lon <- which(names(dim(subset)) == lon_dim) pos_lat <- which(names(dim(subset)) == lat_dim) pos_lon_dim_in_lons <- which(names(dim(lons)) == lon_dim) pos_lat_dim_in_lons <- which(names(dim(lons)) == lat_dim) if ((pos_lon > pos_lat && pos_lon_dim_in_lons < pos_lat_dim_in_lons) || (pos_lon < pos_lat && pos_lon_dim_in_lons > pos_lat_dim_in_lons)) { new_pos <- 1:length(dim(subset)) new_pos[pos_lon] <- pos_lat new_pos[pos_lat] <- pos_lon subset <- .aperm2(subset, new_pos) } # The unlimited dimension should be placed in the last position if ('time' %in% names(dim(subset)) && which(names(dim(subset)) == 'time') != length(dim(subset))) { new_pos <- 2:length(dim(subset)) new_pos[length(dim(subset))] <- 1 subset <- .aperm2(subset, new_pos) } } # dims_before_crop <- dim(subset) # Make sure subset goes along with metadata if (is.null(unlimited_dim)) { easyNCDF::ArrayToNc(setNames(list(subset, lons, lats), c('var', lon_var_name, lat_var_name)), tmp_file) } else { easyNCDF::ArrayToNc(setNames(list(subset, lons, lats, time_attr), c('var', lon_var_name, lat_var_name, 'time')), tmp_file) } } else { if (is_irregular) { pos_lon <- which(names(dim(data_array)) == lon_dim) pos_lat <- which(names(dim(data_array)) == lat_dim) pos_lon_dim_in_lons <- which(names(dim(lons)) == lon_dim) pos_lat_dim_in_lons <- which(names(dim(lons)) == lat_dim) if ((pos_lon > pos_lat && pos_lon_dim_in_lons < pos_lat_dim_in_lons) || (pos_lon < pos_lat && pos_lon_dim_in_lons > pos_lat_dim_in_lons)) { new_pos <- 1:length(dim(data_array)) new_pos[pos_lon] <- pos_lat new_pos[pos_lat] <- pos_lon data_array <- .aperm2(data_array, new_pos) } } # dims_before_crop <- dim(data_array) if (is.null(unlimited_dim)) { easyNCDF::ArrayToNc(setNames(list(data_array, lons, lats), c('var', lon_var_name, lat_var_name)), tmp_file) } else { easyNCDF::ArrayToNc(setNames(list(data_array, lons, lats, time_attr), c('var', lon_var_name, lat_var_name, 'time')), tmp_file) } } sellonlatbox <- '' if (crop) { sellonlatbox <- paste0('sellonlatbox,', format(lon_extremes[1], scientific = FALSE), ',', format(lon_extremes[2], scientific = FALSE), ',', format(lat_extremes[1], scientific = FALSE), ',', format(lat_extremes[2], scientific = FALSE), ' -') } err <- try({ system(paste0("cdo -s ", sellonlatbox, "remap", method, ",", grid, " ", tmp_file, " ", tmp_file2), ignore.stdout = T, ignore.stderr = T) }) file.remove(tmp_file) if (is(err, 'try-error') || err > 0) { stop("CDO remap failed. Possible problem: parameter 'grid'.") } ncdf_remapped <- nc_open(tmp_file2) if (!lons_lats_taken) { found_dim_names <- sapply(ncdf_remapped$var$var$dim, '[[', 'name') found_lon_dim <- found_dim_names[which(found_dim_names %in% .KnownLonNames())[1]] found_lat_dim <- found_dim_names[which(found_dim_names %in% .KnownLatNames())[1]] found_lon_dim_size <- length(ncdf_remapped$dim[[found_lon_dim]]$vals) found_lat_dim_size <- length(ncdf_remapped$dim[[found_lat_dim]]$vals) found_var_names <- names(ncdf_remapped$var) found_lon_var_name <- which(found_var_names %in% .KnownLonNames()) found_lat_var_name <- which(found_var_names %in% .KnownLatNames()) if (length(found_lon_var_name) > 0) { found_lon_var_name <- found_var_names[found_lon_var_name[1]] } else { found_lon_var_name <- NULL } if (length(found_lat_var_name) > 0) { found_lat_var_name <- found_var_names[found_lat_var_name[1]] } else { found_lat_var_name <- NULL } if (length(found_lon_var_name) > 0) { found_lons <- ncvar_get(ncdf_remapped, found_lon_var_name, collapse_degen = FALSE) } else { found_lons <- ncdf_remapped$dim[[found_lon_dim]]$vals dim(found_lons) <- found_lon_dim_size } if (length(found_lat_var_name) > 0) { found_lats <- ncvar_get(ncdf_remapped, found_lat_var_name, collapse_degen = FALSE) } else { found_lats <- ncdf_remapped$dim[[found_lat_dim]]$vals dim(found_lats) <- found_lat_dim_size } if (length(dim(lons)) == length(dim(found_lons))) { new_lon_name <- lon_dim } else { new_lon_name <- found_lon_dim } if (length(dim(lats)) == length(dim(found_lats))) { new_lat_name <- lat_dim } else { new_lat_name <- found_lat_dim } if (length(dim(found_lons)) > 1) { if (which(sapply(ncdf_remapped$var$lon$dim, '[[', 'name') == found_lon_dim) < which(sapply(ncdf_remapped$var$lon$dim, '[[', 'name') == found_lat_dim)) { names(dim(found_lons)) <- c(new_lon_name, new_lat_name) } else { names(dim(found_lons)) <- c(new_lat_name, new_lon_name) } } else { names(dim(found_lons)) <- new_lon_name } if (length(dim(found_lats)) > 1) { if (which(sapply(ncdf_remapped$var$lat$dim, '[[', 'name') == found_lon_dim) < which(sapply(ncdf_remapped$var$lat$dim, '[[', 'name') == found_lat_dim)) { names(dim(found_lats)) <- c(new_lon_name, new_lat_name) } else { names(dim(found_lats)) <- c(new_lat_name, new_lon_name) } } else { names(dim(found_lats)) <- new_lat_name } lons_lats_taken <- TRUE } if (!is.null(dims_to_iterate)) { if (is.null(result_array)) { if (return_array) { new_dims <- dim(data_array) new_dims[c(lon_dim, lat_dim)] <- c(found_lon_dim_size, found_lat_dim_size) lon_pos <- which(names(new_dims) == lon_dim) lat_pos <- which(names(new_dims) == lat_dim) # Fix issue 259, expected order from CDO output is lon lat # If is irregular, lat and lon position need to be checked: if (is_irregular) { if (lon_pos > lat_pos) { new_pos <- 1:length(new_dims) new_pos[lon_pos] <- lat_pos new_pos[lat_pos] <- lon_pos new_dims <- new_dims[new_pos] } } result_array <- array(dim = new_dims) store_indices <- as.list(rep(TRUE, length(dim(result_array)))) } } if (return_array) { store_indices[dims_to_iterate] <- as.list(slice_indices) # If is irregular, the order of dimenesions in result_array and file may be different and need to be checked before reading the temporal file: if (is_irregular) { test_dims <- dim(ncvar_get(ncdf_remapped, 'var', collapse_degen = FALSE)) test_dims <- test_dims[which(test_dims > 1)] pos_test_dims <- match(dim(result_array), test_dims) if (is.unsorted(pos_test_dims, na.rm = TRUE)) { # pos_new_dims is used later in the code. Don't overwrite pos_new_dims <- 1:length(dim(result_array)) pos_new_dims[which(!is.na(pos_test_dims))] <- match(test_dims, dim(result_array)) backup_result_array_dims <- dim(result_array) dim(result_array) <- dim(result_array)[pos_new_dims] } } result_array <- do.call('[<-', c(list(x = result_array), store_indices, list(value = ncvar_get(ncdf_remapped, 'var', collapse_degen = FALSE)))) } } else { new_dims <- dim(data_array) new_dims[c(lon_dim, lat_dim)] <- c(found_lon_dim_size, found_lat_dim_size) if (is_irregular) { lon_pos <- which(names(new_dims) == lon_dim) lat_pos <- which(names(new_dims) == lat_dim) if (lon_pos > lat_pos) { new_pos <- 1:length(new_dims) new_pos[lon_pos] <- lat_pos new_pos[lat_pos] <- lon_pos new_dims <- new_dims[new_pos] } } result_array <- ncvar_get(ncdf_remapped, 'var', collapse_degen = FALSE) dim(result_array) <- new_dims } nc_close(ncdf_remapped) file.remove(tmp_file2) } # If is irregular, the order of dimension may need to be recovered after reading all the file: if (is_irregular & (!is.null(dims_to_iterate))) { if (exists('pos_new_dims')) { pos_new_dims <- 1:length(dim(result_array)) dims_to_change <- match(backup_result_array_dims, dim(result_array)) pos_new_dims[which(dims_to_change != 1)] <- dims_to_change[which(dims_to_change != 1)] result_array <- .aperm2(result_array, pos_new_dims) } } if (!is.null(permutation)) { dim_backup <- dim(result_array) result_array <- aperm(result_array, permutation_back) dim(result_array) <- dim_backup[permutation_back] } # Now restore the metadata result_is_irregular <- FALSE if (length(dim(found_lats)) > 1 && length(dim(found_lons)) > 1) { result_is_irregular <- TRUE } attribute_backup[['dim']][which(names(dim(result_array)) == lon_dim)] <- dim(result_array)[lon_dim] attribute_backup[['dim']][which(names(dim(result_array)) == lat_dim)] <- dim(result_array)[lat_dim] names(attribute_backup[['dim']])[which(names(dim(result_array)) == lon_dim)] <- new_lon_name names(attribute_backup[['dim']])[which(names(dim(result_array)) == lat_dim)] <- new_lat_name if (!is.null(attribute_backup[['variables']]) && (length(attribute_backup[['variables']]) > 0)) { for (var in 1:length(attribute_backup[['variables']])) { if (length(attribute_backup[['variables']][[var]][['dim']]) > 0) { for (dim in 1:length(attribute_backup[['variables']][[var]][['dim']])) { dim_name <- NULL if ('name' %in% names(attribute_backup[['variables']][[var]][['dim']][[dim]])) { dim_name <- attribute_backup[['variables']][[var]][['dim']][[dim]][['name']] if (dim_name %in% c(lon_dim, lat_dim)) { if (dim_name == lon_dim) { attribute_backup[['variables']][[var]][['dim']][[dim]][['name']] <- new_lon_name } else { attribute_backup[['variables']][[var]][['dim']][[dim]][['name']] <- new_lat_name } } } else if (!is.null(names(attribute_backup[['variables']][[var]][['dim']]))) { dim_name <- names(attribute_backup[['variables']][[var]][['dim']])[dim] if (dim_name %in% c(lon_dim, lat_dim)) { if (dim_name == lon_dim) { names(attribute_backup[['variables']][[var]][['dim']])[which(names(attribute_backup[['variables']][[var]][['dim']]) == lon_dim)] <- new_lon_name } else { names(attribute_backup[['variables']][[var]][['dim']])[which(names(attribute_backup[['variables']][[var]][['dim']]) == lat_dim)] <- new_lat_name } } } if (!is.null(dim_name)) { if (dim_name %in% c(lon_dim, lat_dim)) { if (dim_name == lon_dim) { new_vals <- found_lons[TRUE] } else if (dim_name == lat_dim) { new_vals <- found_lats[TRUE] } if (!is.null(attribute_backup[['variables']][[var]][['dim']][[dim]][['len']])) { attribute_backup[['variables']][[var]][['dim']][[dim]][['len']] <- length(new_vals) } if (!is.null(attribute_backup[['variables']][[var]][['dim']][[dim]][['vals']])) { if (!result_is_irregular) { attribute_backup[['variables']][[var]][['dim']][[dim]][['vals']] <- new_vals } else { attribute_backup[['variables']][[var]][['dim']][[dim]][['vals']] <- 1:length(new_vals) } } } } } } if (!is_irregular && result_is_irregular) { attribute_backup[['coordinates']] <- paste(lon_var_name, lat_var_name) } else if (is_irregular && !result_is_irregular) { attribute_backup[['coordinates']] <- NULL } } } attributes(result_array) <- attribute_backup lons_attr_bk[['dim']] <- dim(found_lons) if (!is.null(lons_attr_bk[['variables']]) && (length(lons_attr_bk[['variables']]) > 0)) { for (var in 1:length(lons_attr_bk[['variables']])) { if (length(lons_attr_bk[['variables']][[var]][['dim']]) > 0) { dims_to_remove <- NULL for (dim in 1:length(lons_attr_bk[['variables']][[var]][['dim']])) { dim_name <- NULL if ('name' %in% names(lons_attr_bk[['variables']][[var]][['dim']][[dim]])) { dim_name <- lons_attr_bk[['variables']][[var]][['dim']][[dim]][['name']] if (dim_name %in% c(lon_dim, lat_dim)) { if (dim_name == lon_dim) { lons_attr_bk[['variables']][[var]][['dim']][[dim]][['name']] <- new_lon_name } else { lons_attr_bk[['variables']][[var]][['dim']][[dim]][['name']] <- new_lat_name } } } else if (!is.null(names(lons_attr_bk[['variables']][[var]][['dim']]))) { dim_name <- names(lons_attr_bk[['variables']][[var]][['dim']])[dim] if (dim_name %in% c(lon_dim, lat_dim)) { if (dim_name == lon_dim) { names(lons_attr_bk[['variables']][[var]][['dim']])[which(names(lons_attr_bk[['variables']][[var]][['dim']]) == lon_dim)] <- new_lon_name } else { names(lons_attr_bk[['variables']][[var]][['dim']])[which(names(lons_attr_bk[['variables']][[var]][['dim']]) == lat_dim)] <- new_lat_name } } } if (!is.null(dim_name)) { if (dim_name %in% c(lon_dim, lat_dim)) { if (dim_name == lon_dim) { new_vals <- found_lons[TRUE] } else if (dim_name == lat_dim) { new_vals <- found_lats[TRUE] if (!result_is_irregular) { dims_to_remove <- c(dims_to_remove, dim) } } if (!is.null(lons_attr_bk[['variables']][[var]][['dim']][[dim]][['len']])) { lons_attr_bk[['variables']][[var]][['dim']][[dim]][['len']] <- length(new_vals) } if (!is.null(lons_attr_bk[['variables']][[var]][['dim']][[dim]][['vals']])) { if (!result_is_irregular) { lons_attr_bk[['variables']][[var]][['dim']][[dim]][['vals']] <- new_vals } else { lons_attr_bk[['variables']][[var]][['dim']][[dim]][['vals']] <- 1:length(new_vals) } } } } } if (length(dims_to_remove) > 1) { lons_attr_bk[['variables']][[var]][['dim']] <- lons_attr_bk[['variables']][[var]][['dim']][[-dims_to_remove]] } } } names(lons_attr_bk[['variables']])[1] <- lon_var_name lons_attr_bk[['variables']][[1]][['units']] <- 'degrees_east' } attributes(found_lons) <- lons_attr_bk lats_attr_bk[['dim']] <- dim(found_lats) if (!is.null(lats_attr_bk[['variables']]) && (length(lats_attr_bk[['variables']]) > 0)) { for (var in 1:length(lats_attr_bk[['variables']])) { if (length(lats_attr_bk[['variables']][[var]][['dim']]) > 0) { dims_to_remove <- NULL for (dim in 1:length(lats_attr_bk[['variables']][[var]][['dim']])) { dim_name <- NULL if ('name' %in% names(lats_attr_bk[['variables']][[var]][['dim']][[dim]])) { dim_name <- lats_attr_bk[['variables']][[var]][['dim']][[dim]][['name']] if (dim_name %in% c(lon_dim, lat_dim)) { if (dim_name == lon_dim) { lons_attr_bk[['variables']][[var]][['dim']][[dim]][['name']] <- new_lon_name } else { lons_attr_bk[['variables']][[var]][['dim']][[dim]][['name']] <- new_lat_name } } } else if (!is.null(names(lats_attr_bk[['variables']][[var]][['dim']]))) { dim_name <- names(lats_attr_bk[['variables']][[var]][['dim']])[dim] if (dim_name %in% c(lon_dim, lat_dim)) { if (dim_name == lon_dim) { names(lats_attr_bk[['variables']][[var]][['dim']])[which(names(lats_attr_bk[['variables']][[var]][['dim']]) == lon_dim)] <- new_lon_name } else { names(lats_attr_bk[['variables']][[var]][['dim']])[which(names(lats_attr_bk[['variables']][[var]][['dim']]) == lat_dim)] <- new_lat_name } } } if (!is.null(dim_name)) { if (dim_name %in% c(lon_dim, lat_dim)) { if (dim_name == lon_dim) { new_vals <- found_lons[TRUE] if (!result_is_irregular) { dims_to_remove <- c(dims_to_remove, dim) } } else if (dim_name == lat_dim) { new_vals <- found_lats[TRUE] } if (!is.null(lats_attr_bk[['variables']][[var]][['dim']][[dim]][['len']])) { lats_attr_bk[['variables']][[var]][['dim']][[dim]][['len']] <- length(new_vals) } if (!is.null(lats_attr_bk[['variables']][[var]][['dim']][[dim]][['vals']])) { if (!result_is_irregular) { lats_attr_bk[['variables']][[var]][['dim']][[dim]][['vals']] <- new_vals } else { lats_attr_bk[['variables']][[var]][['dim']][[dim]][['vals']] <- 1:length(new_vals) } } } } } if (length(dims_to_remove) > 1) { lats_attr_bk[['variables']][[var]][['dim']] <- lats_attr_bk[['variables']][[var]][['dim']][[-dims_to_remove]] } } } names(lats_attr_bk[['variables']])[1] <- lat_var_name lats_attr_bk[['variables']][[1]][['units']] <- 'degrees_north' } attributes(found_lats) <- lats_attr_bk } list(data_array = if (return_array) { if (interpolation_needed) { result_array } else { data_array } } else { NULL }, lons = found_lons, lats = found_lats) }