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#'@importFrom abind abind
#'@importFrom plyr take

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## Function to tell if a regexpr() match is a complete match to a specified name
.IsFullMatch <- function(x, name) {
  ifelse(x > 0 && attributes(x)$match.length == nchar(name), TRUE, FALSE)
}

.ConfigReplaceVariablesInString <- function(string, replace_values, allow_undefined_key_vars = FALSE) {
  # This function replaces all the occurrences of a variable in a string by 
  # their corresponding string stored in the replace_values.
  if (length(strsplit(string, "\\$")[[1]]) > 1) {
    parts <- strsplit(string, "\\$")[[1]]
    output <- ""
    i <- 0
    for (part in parts) {
      if (i %% 2 == 0) {
        output <- paste(output, part, sep = "")
      } else {
        if (part %in% names(replace_values)) {
          output <- paste(output, .ConfigReplaceVariablesInString(replace_values[[part]], replace_values, allow_undefined_key_vars), sep = "")
        } else if (allow_undefined_key_vars) {
          output <- paste0(output, "$", part, "$")
        } else {
          stop(paste('Error: The variable $', part, '$ was not defined in the configuration file.', sep = ''))
        }
      }
      i <- i + 1
    }
    output
  } else {
    string
  }
}

.KnownLonNames <- function() {
  known_lon_names <- c('lon', 'longitude', 'x', 'i', 'nav_lon')
}

.KnownLatNames <- function() {
  known_lat_names <- c('lat', 'latitude', 'y', 'j', 'nav_lat')
}

.t2nlatlon <- function(t) {
  ## As seen in cdo's griddes.c: ntr2nlat()
  nlats <- (t * 3 + 1) / 2
  if ((nlats > 0) && (nlats - trunc(nlats) >= 0.5)) {
    nlats <- ceiling(nlats)
  } else {
    nlats <- round(nlats)
  }
  if (nlats %% 2 > 0) {
    nlats <- nlats + 1
  }
  ## As seen in cdo's griddes.c: compNlon(), and as specified in ECMWF
  nlons <- 2 * nlats
  keep_going <- TRUE
  while (keep_going) {
    n <- nlons
    if (n %% 8 == 0) n <- trunc(n / 8)
    while (n %% 6 == 0) n <- trunc(n / 6)
    while (n %% 5 == 0) n <- trunc(n / 5)
    while (n %% 4 == 0) n <- trunc(n / 4)
    while (n %% 3 == 0) n <- trunc(n / 3)
    if (n %% 2 == 0) n <- trunc(n / 2)
    if (n <= 8) {
      keep_going <- FALSE
    } else {
      nlons <- nlons + 2
      if (nlons > 9999) {
        stop("Error: pick another gaussian grid truncation. It doesn't fulfill the standards to apply FFT.")
      }
    }
  }
  c(nlats, nlons)
}

.nlat2t <- function(nlats) {
  trunc((nlats * 2 - 1) / 3)
}

.LoadDataFile <- function(work_piece, explore_dims = FALSE, silent = FALSE) {
  # The purpose, working modes, inputs and outputs of this function are
  # explained in ?LoadDataFile
  #suppressPackageStartupMessages({library(ncdf4)})
  #suppressPackageStartupMessages({library(bigmemory)})
  #suppressPackageStartupMessages({library(plyr)})
  # Auxiliar function to convert array indices to lineal indices
  arrayIndex2VectorIndex <- function(indices, dims) {
    if (length(indices) > length(dims)) {
      stop("Error: indices do not match dimensions in arrayIndex2VectorIndex.")
    }
    position <- 1
    dims <- rev(dims)
    indices <- rev(indices)
    for (i in 1:length(indices)) {
      position <- position + (indices[i] - 1) * prod(dims[-c(1:i)])
    }
    position
  }
  .t2nlatlon <- function(t) {
    ## As seen in cdo's griddes.c: ntr2nlat()
    nlats <- (t * 3 + 1) / 2
    if ((nlats > 0) && (nlats - trunc(nlats) >= 0.5)) {
      nlats <- ceiling(nlats)
    } else {
      nlats <- round(nlats)
    }
    if (nlats %% 2 > 0) {
      nlats <- nlats + 1
    }
    ## As seen in cdo's griddes.c: compNlon(), and as specified in ECMWF
    nlons <- 2 * nlats
    keep_going <- TRUE
    while (keep_going) {
      n <- nlons
      if (n %% 8 == 0) n <- trunc(n / 8)
      while (n %% 6 == 0) n <- trunc(n / 6)
      while (n %% 5 == 0) n <- trunc(n / 5)
      while (n %% 4 == 0) n <- trunc(n / 4)
      while (n %% 3 == 0) n <- trunc(n / 3)
      if (n %% 2 == 0) n <- trunc(n / 2)
      if (n <= 8) {
        keep_going <- FALSE
      } else {
        nlons <- nlons + 2
        if (nlons > 9999) {
          stop("Error: pick another gaussian grid truncation. It doesn't fulfill the standards to apply FFT.")
        }
      }
    }
    c(nlats, nlons)
  }
  
  .nlat2t <- function(nlats) {
    trunc((nlats * 2 - 1) / 3)
  }

  found_file <- NULL
  dims <- NULL
  grid_name <- units <- var_long_name <- NULL
  is_2d_var <- array_across_gw <- NULL
  data_across_gw <- NULL

  filename <- work_piece[['filename']]
  namevar <- work_piece[['namevar']]
  output <- work_piece[['output']]
  # The names of all data files in the directory of the repository that match 
  # the pattern are obtained.
  if (length(grep("^http", filename)) > 0) {
    is_url <- TRUE
    files <- filename
    ## TODO: Check that the user is not using shell globbing exps.
  } else {
    is_url <- FALSE
    files <- Sys.glob(filename)
  }

  # If we don't find any, we leave the flag 'found_file' with a NULL value.
  if (length(files) > 0) {
    # The first file that matches the pattern is chosen and read.
    filename <- head(files, 1)
    filein <- filename
    found_file <- filename
    mask <- work_piece[['mask']]

    if (!silent) {
      if (explore_dims) {
        .message(paste("Exploring dimensions...", filename))
      }
      ##} else {
      ##  cat(paste("* Reading & processing data...", filename, '\n'))
      ##}
    }

    # We will fill in 'expected_dims' with the names of the expected dimensions of
    # the data array we'll retrieve from the file.
    expected_dims <- NULL
    remap_needed <- FALSE
    # But first we open the file and work out whether the requested variable is 2d
    fnc <- nc_open(filein)
    if (!(namevar %in% names(fnc$var))) {
      stop(paste("Error: The variable", namevar, "is not defined in the file", filename))
    }
    var_long_name <- fnc$var[[namevar]]$longname
    units <- fnc$var[[namevar]]$units
    file_dimnames <- unlist(lapply(fnc$var[[namevar]][['dim']], '[[', 'name'))
    # The following two 'ifs' are to allow for 'lon'/'lat' by default, instead of 
    # 'longitude'/'latitude'.
    if (!(work_piece[['dimnames']][['lon']] %in% file_dimnames) &&
        (work_piece[['dimnames']][['lon']] == 'longitude') &&
        ('lon' %in% file_dimnames)) {
      work_piece[['dimnames']][['lon']] <- 'lon'
    }
    if (!(work_piece[['dimnames']][['lat']] %in% file_dimnames) &&
        (work_piece[['dimnames']][['lat']] == 'latitude') &&
        ('lat' %in% file_dimnames)) {
      work_piece[['dimnames']][['lat']] <- 'lat'
    }
    if (is.null(work_piece[['is_2d_var']])) {
      is_2d_var <- all(c(work_piece[['dimnames']][['lon']], 
                         work_piece[['dimnames']][['lat']]) %in%
                       unlist(lapply(fnc$var[[namevar]][['dim']], 
                                     '[[', 'name')))
    } else {
      is_2d_var <- work_piece[['is_2d_var']]
    }
    if ((is_2d_var || work_piece[['is_file_per_dataset']])) {
      if (Sys.which("cdo")[[1]] == "") {
        stop("Error: CDO libraries not available")
      }
      cdo_version <- as.numeric_version(strsplit(suppressWarnings(system2("cdo", args = '-V', stderr = TRUE))[[1]], ' ')[[1]][5])
    }
    # If the variable to load is 2-d, we need to determine whether:
    #  - interpolation is needed
    #  - subsetting is requested
    if (is_2d_var) {
      ## We read the longitudes and latitudes from the file.
      lon <- ncvar_get(fnc, work_piece[['dimnames']][['lon']])
      lat <- ncvar_get(fnc, work_piece[['dimnames']][['lat']])
      first_lon_in_original_file <- lon[1]
      # If a common grid is requested or we are exploring the file dimensions
      # we need to read the grid type and size of the file to finally work out the 
      # CDO grid name.
      if (!is.null(work_piece[['grid']]) || explore_dims) {
        # Here we read the grid type and its number of longitudes and latitudes
        file_info <- system(paste('cdo -s griddes', filein, '2> /dev/null'), intern = TRUE)
        grids_positions <- grep('# gridID', file_info)
        if (length(grids_positions) < 1) {
          stop("The grid should be defined in the files.")
        }
        grids_first_lines <- grids_positions + 2
        grids_last_lines <- c((grids_positions - 2)[-1], length(file_info))
        grids_info <- as.list(1:length(grids_positions))
        grids_info <- lapply(grids_info, function (x) file_info[grids_first_lines[x]:grids_last_lines[x]])
        grids_info <- lapply(grids_info, function (x) gsub("  *", " ", x))
        grids_info <- lapply(grids_info, function (x) gsub("^ | $", "", x))
        grids_info <- lapply(grids_info, function (x) unlist(strsplit(x, " | = ")))
        grids_types <- unlist(lapply(grids_info, function (x) x[grep('gridtype', x) + 1]))
        grids_matches <- unlist(lapply(grids_info, function (x) {
          nlons <- if (length(grep('xsize', x)) > 0) {
                     as.numeric(x[grep('xsize', x) + 1])
                   } else {
                     NA
                   }
          nlats <- if (length(grep('ysize', x)) > 0) {
                    as.numeric(x[grep('ysize', x) + 1])
                  } else {
                    NA
                  }
          result <- FALSE
          if (!any(is.na(c(nlons, nlats)))) {
            if ((nlons == length(lon)) && 
                (nlats == length(lat))) {
              result <- TRUE
            }
          }
          result
        }))
        grids_matches <- grids_matches[which(grids_types %in% c('gaussian', 'lonlat'))]
        grids_info <- grids_info[which(grids_types %in% c('gaussian', 'lonlat'))]
        grids_types <- grids_types[which(grids_types %in% c('gaussian', 'lonlat'))]
        if (length(grids_matches) == 0) {
          stop("Error: Only 'gaussian' and 'lonlat' grids supported. See e.g: cdo sinfo ", filename)
        }
        if (sum(grids_matches) > 1) {
          if ((all(grids_types[which(grids_matches)] == 'gaussian') || 
               all(grids_types[which(grids_matches)] == 'lonlat')) && 
               all(unlist(lapply(grids_info[which(grids_matches)], identical, 
                                 grids_info[which(grids_matches)][[1]])))) {
            grid_type <- grids_types[which(grids_matches)][1]
          } else {
            stop("Error: Load() can't disambiguate: More than one lonlat/gaussian grids with the same size as the requested variable defined in ", filename)
          }
        } else if (sum(grids_matches) == 1) {
          grid_type <- grids_types[which(grids_matches)]
        } else {
          stop("Unexpected error.")
        }
        grid_lons <- length(lon)
        grid_lats <- length(lat)
        # Convert to CDO grid name as seen in cdo's griddes.c: nlat2ntr()
        if (grid_type == 'lonlat') {
          grid_name <- paste0('r', grid_lons, 'x', grid_lats)
        } else {
          grid_name <- paste0('t', .nlat2t(grid_lats), 'grid')
        }
      }
      # If a common grid is requested, we will also calculate its size which we will use
      # later on.
      if (!is.null(work_piece[['grid']])) {
        # Now we calculate the common grid type and its lons and lats
        if (length(grep('^t\\d{1,+}grid$', work_piece[['grid']])) > 0) {
          common_grid_type <- 'gaussian'
          common_grid_res <- as.numeric(strsplit(work_piece[['grid']], '[^0-9]{1,+}')[[1]][2])
          nlonlat <- .t2nlatlon(common_grid_res)
          common_grid_lats <- nlonlat[1]
          common_grid_lons <- nlonlat[2]
        } else if (length(grep('^r\\d{1,+}x\\d{1,+}$', work_piece[['grid']])) > 0) {
          common_grid_type <- 'lonlat'
          common_grid_lons <- as.numeric(strsplit(work_piece[['grid']], '[^0-9]{1,+}')[[1]][2])
          common_grid_lats <- as.numeric(strsplit(work_piece[['grid']], '[^0-9]{1,+}')[[1]][3])
        } else {
          stop("Error: Only supported grid types in parameter 'grid' are t<RES>grid and r<NX>x<NY>")
        }
      } else {
        ## If no 'grid' is specified, there is no common grid.
        ## But these variables are filled in for consistency in the code.
        common_grid_lons <- length(lon)
        common_grid_lats <- length(lat)
      }
      first_common_grid_lon <- 0
      last_common_grid_lon <- 360 - 360/common_grid_lons
      ## This is not true for gaussian grids or for some regular grids, but 
      ## is a safe estimation
      first_common_grid_lat <- -90
      last_common_grid_lat <- 90
      # And finally determine whether interpolation is needed or not
      remove_shift <- FALSE
      if (!is.null(work_piece[['grid']])) {
        if ((grid_lons != common_grid_lons) || 
            (grid_lats != common_grid_lats) || 
            (grid_type != common_grid_type) ||
            ((lon[1] != first_common_grid_lon) 
             && !work_piece[['single_dataset']])) {
          if (grid_lons == common_grid_lons && grid_lats == common_grid_lats &&
              grid_type == common_grid_type && lon[1] != first_common_grid_lon &&
              !work_piece[['single_dataset']]) {
            remove_shift <- TRUE
          }
          remap_needed <- TRUE
          common_grid_name <- work_piece[['grid']]
        }
      } else if ((lon[1] != first_common_grid_lon) && explore_dims && 
                 !work_piece[['single_dataset']]) {
        remap_needed <- TRUE
        common_grid_name <- grid_name
        remove_shift <- TRUE
      }
      if (remap_needed && (work_piece[['remap']] == 'con') && 
          (cdo_version >= as.numeric_version('1.7.0'))) {
        work_piece[['remap']] <- 'ycon'
      }
      if (remove_shift && !explore_dims) {
        if (!is.null(work_piece[['progress_amount']])) {
          cat("\n")
        }
        cat(paste0("! Warning: the dataset with index ", 
            tail(work_piece[['indices']], 1), " in '", 
            work_piece[['dataset_type']], "' doesn't start at longitude 0 and will be re-interpolated in order to align its longitudes with the standard CDO grids definable with the names 't<RES>grid' or 'r<NX>x<NY>', which are by definition starting at the longitude 0.\n"))
        if (!is.null(mask)) {
          cat(paste0("! Warning: a mask was provided for the dataset with index ",    
              tail(work_piece[['indices']], 1), " in '",
              work_piece[['dataset_type']], "'. This dataset has been re-interpolated to align its longitudes to start at 0. You must re-interpolate the corresponding mask to align its longitudes to start at 0 as well, if you haven't done so yet. Running cdo remapcon,", common_grid_name, " original_mask_file.nc new_mask_file.nc will fix it.\n"))
        }
      }
      if (remap_needed && (grid_lons < common_grid_lons || grid_lats < common_grid_lats)) {
        if (!is.null(work_piece[['progress_amount']])) {
          cat("\n")
        }
        if (!explore_dims) {
          cat(paste0("! Warning: the dataset with index ", tail(work_piece[['indices']], 1), 
                     " in '", work_piece[['dataset_type']], "' is originally on ",
                     "a grid coarser than the common grid and it has been ",
                     "extrapolated. Check the results carefully. It is ",
                     "recommended to specify as common grid the coarsest grid ",
                     "among all requested datasets via the parameter 'grid'.\n"))
        }
      }
      # Now calculate if the user requests for a lonlat subset or for the 
      # entire field
      lonmin <- work_piece[['lon_limits']][1]
      lonmax <- work_piece[['lon_limits']][2]
      latmin <- work_piece[['lat_limits']][1]
      latmax <- work_piece[['lat_limits']][2]
      lon_subsetting_requested <- FALSE
      lonlat_subsetting_requested <- FALSE
      if (lonmin <= lonmax) {
        if ((lonmin > first_common_grid_lon) || (lonmax < last_common_grid_lon)) {
          lon_subsetting_requested <- TRUE
        }
      } else {
        if ((lonmin - lonmax) > 360/common_grid_lons) {
          lon_subsetting_requested <- TRUE
        } else {
          gap_width <- floor(lonmin / (360/common_grid_lons)) - 
                       floor(lonmax / (360/common_grid_lons))
          if (gap_width > 0) { 
            if (!(gap_width == 1 && (lonmin %% (360/common_grid_lons) == 0) && 
                  (lonmax %% (360/common_grid_lons) == 0))) {
              lon_subsetting_requested <- TRUE
            }
          }
        }
      }
      if ((latmin > first_common_grid_lat) || (latmax < last_common_grid_lat)
          || (lon_subsetting_requested)) {
        lonlat_subsetting_requested <- TRUE
      }
      # Now that we know if subsetting was requested, we can say if final data
      # will go across greenwich
      if (lonmax < lonmin) {
        data_across_gw <- TRUE
      } else {
        data_across_gw <- !lon_subsetting_requested
      }

      # When remap is needed but no subsetting, the file is copied locally
      # so that cdo works faster, and then interpolated.
      # Otherwise the file is kept as is and the subset will have to be 
      # interpolated still.
      if (!lonlat_subsetting_requested && remap_needed) {
        nc_close(fnc)
        filecopy <- tempfile(pattern = "load", fileext = ".nc")
        file.copy(filein, filecopy)
        filein <- tempfile(pattern = "loadRegridded", fileext = ".nc")
        system(paste0("cdo -s remap", work_piece[['remap']], ",", 
                      common_grid_name, 
                      " -selname,", namevar, " ", filecopy, " ", filein, 
                      " 2>/dev/null", sep = ""))
        file.remove(filecopy)
        work_piece[['dimnames']][['lon']] <- 'lon'
        work_piece[['dimnames']][['lat']] <- 'lat'
        fnc <- nc_open(filein)
        lon <- ncvar_get(fnc, work_piece[['dimnames']][['lon']])
        lat <- ncvar_get(fnc, work_piece[['dimnames']][['lat']])
      }

      # Read and check also the mask
      if (!is.null(mask)) {
        ###mask_file <- tempfile(pattern = 'loadMask', fileext = '.nc')
        if (is.list(mask)) {
          if (!file.exists(mask[['path']])) {
            stop(paste("Error: Couldn't find the mask file", mask[['path']]))
          }
          mask_file <- mask[['path']]
          ###file.copy(work_piece[['mask']][['path']], mask_file)
          fnc_mask <- nc_open(mask_file)
          vars_in_mask <- sapply(fnc_mask$var, '[[', 'name')
          if ('nc_var_name' %in% names(mask)) {
            if (!(mask[['nc_var_name']] %in% 
                  vars_in_mask)) {
              stop(paste("Error: couldn't find variable", mask[['nc_var_name']], 
                         "in the mask file", mask[['path']]))
            }
          } else {
            if (length(vars_in_mask) != 1) {
              stop(paste("Error: one and only one non-coordinate variable should be defined in the mask file", 
                   mask[['path']], "if the component 'nc_var_name' is not specified. Currently found: ", 
                   paste(vars_in_mask, collapse = ', '), "."))
            } else {
              mask[['nc_var_name']] <- vars_in_mask
            }
          }
          if (sum(fnc_mask$var[[mask[['nc_var_name']]]]$size > 1) != 2) {
            stop(paste0("Error: the variable '", 
                 mask[['nc_var_name']], 
                 "' must be defined only over the dimensions '", 
                 work_piece[['dimnames']][['lon']], "' and '", 
                 work_piece[['dimnames']][['lat']], 
                 "' in the mask file ", 
                 mask[['path']]))
          }
          mask <- ncvar_get(fnc_mask, mask[['nc_var_name']], collapse_degen = TRUE)
          nc_close(fnc_mask)
        ###  mask_lon <- ncvar_get(fnc_mask, work_piece[['dimnames']][['lon']])
        ###  mask_lat <- ncvar_get(fnc_mask, work_piece[['dimnames']][['lat']])
        ###} else {
        ###  dim_longitudes <- ncdim_def(work_piece[['dimnames']][['lon']], "degrees_east", lon)
        ###  dim_latitudes <- ncdim_def(work_piece[['dimnames']][['lat']], "degrees_north", lat)
        ###  ncdf_var <- ncvar_def('LSM', "", list(dim_longitudes, dim_latitudes), NA, 'double')
        ###  fnc_mask <- nc_create(mask_file, list(ncdf_var))
        ###  ncvar_put(fnc_mask, ncdf_var, work_piece[['mask']])
        ###  nc_close(fnc_mask)
        ###  fnc_mask <- nc_open(mask_file)
        ###  work_piece[['mask']] <- list(path = mask_file, nc_var_name = 'LSM')
        ###  mask_lon <- lon
        ###  mask_lat <- lat
        ###}
      ###}
        ### Now ready to check that the mask is right
        ##if (!(lonlat_subsetting_requested && remap_needed)) {
        ###  if ((dim(mask)[2] != length(lon)) || (dim(mask)[1] != length(lat))) {
        ###    stop(paste("Error: the mask of the dataset with index ", tail(work_piece[['indices']], 1), " in '", work_piece[['dataset_type']], "' is wrong. It must be on the common grid if the selected output type is 'lonlat', 'lon' or 'lat', or 'areave' and 'grid' has been specified. It must be on the grid of the corresponding dataset if the selected output type is 'areave' and no 'grid' has been specified. For more information check ?Load and see help on parameters 'grid', 'maskmod' and 'maskobs'.", sep = ""))
        ###  }
          ###if (!(identical(mask_lon, lon) && identical(mask_lat, lat))) {
          ###  stop(paste0("Error: the longitudes and latitudes in the masks must be identical to the ones in the corresponding data files if output = 'areave' or, if the selected output is 'lon', 'lat' or 'lonlat', the longitudes in the mask file must start by 0 and the latitudes must be ordered from highest to lowest. See\n  ", 
          ###     work_piece[['mask']][['path']], " and ", filein))
          ###}
        }
      }

      lon_indices <- 1:length(lon)
      if (!(lonlat_subsetting_requested && remap_needed)) {
        lon[which(lon < 0)] <- lon[which(lon < 0)] + 360
      }
      if (lonmax >= lonmin) {
        lon_indices <- lon_indices[which(((lon %% 360) >= lonmin) & ((lon %% 360) <= lonmax))]
      } else if (!remap_needed) {
        lon_indices <- lon_indices[which(((lon %% 360) <= lonmax) | ((lon %% 360) >= lonmin))]
      }
      lat_indices <- which(lat >= latmin & lat <= latmax)
      ## In most of the cases the latitudes are ordered from -90 to 90. 
      ## We will reorder them to be in the order from 90 to -90, so mostly 
      ## always the latitudes are reordered.
      ## TODO: This could be avoided in future.
      if (lat[1] < lat[length(lat)]) {
        lat_indices <- lat_indices[length(lat_indices):1]
      }
      if (!is.null(mask) && !(lonlat_subsetting_requested && remap_needed)) {
        if ((dim(mask)[1] != length(lon)) || (dim(mask)[2] != length(lat))) {
          stop(paste("Error: the mask of the dataset with index ", tail(work_piece[['indices']], 1), " in '", work_piece[['dataset_type']], "' is wrong. It must be on the common grid if the selected output type is 'lonlat', 'lon' or 'lat', or 'areave' and 'grid' has been specified. It must be on the grid of the corresponding dataset if the selected output type is 'areave' and no 'grid' has been specified. For more information check ?Load and see help on parameters 'grid', 'maskmod' and 'maskobs'.", sep = ""))
        }
        mask <- mask[lon_indices, lat_indices]
      }
      ## If the user requests subsetting, we must extend the lon and lat limits if possible
      ## so that the interpolation after is done properly
      maximum_extra_points <- work_piece[['remapcells']]
      if (lonlat_subsetting_requested && remap_needed) {
        if ((maximum_extra_points > (head(lon_indices, 1) - 1)) ||
            (maximum_extra_points > (length(lon) - tail(lon_indices, 1)))) {
          ## if the requested number of points goes beyond the left or right
          ## sides of the map, we need to take the entire map so that the 
          ## interpolation works properly
          lon_indices <- 1:length(lon)
        } else {
          extra_points <- min(maximum_extra_points, head(lon_indices, 1) - 1)
          if (extra_points > 0) {
            lon_indices <- c((head(lon_indices, 1) - extra_points):(head(lon_indices, 1) - 1), lon_indices)
          }
          extra_points <- min(maximum_extra_points, length(lon) - tail(lon_indices, 1))
          if (extra_points > 0) {
            lon_indices <- c(lon_indices, (tail(lon_indices, 1) + 1):(tail(lon_indices, 1) + extra_points))
          }
        }
        min_lat_ind <- min(lat_indices)
        max_lat_ind <- max(lat_indices)
        extra_points <- min(maximum_extra_points, min_lat_ind - 1)
        if (extra_points > 0) {
          if (lat[1] < tail(lat, 1)) {
            lat_indices <- c(lat_indices, (min_lat_ind - 1):(min_lat_ind - extra_points))
          } else {
            lat_indices <- c((min_lat_ind - extra_points):(min_lat_ind - 1), lat_indices)
          }
        }
        extra_points <- min(maximum_extra_points, length(lat) - max_lat_ind)
        if (extra_points > 0) {
          if (lat[1] < tail(lat, 1)) {
            lat_indices <- c((max_lat_ind + extra_points):(max_lat_ind + 1), lat_indices)
          } else {
            lat_indices <- c(lat_indices, (max_lat_ind + 1):(max_lat_ind + extra_points))
          }
        }
      }
      lon <- lon[lon_indices]
      lat <- lat[lat_indices]
      expected_dims <- c(work_piece[['dimnames']][['lon']],
                         work_piece[['dimnames']][['lat']])
    } else {
      lon <- 0
      lat <- 0
    }
    # We keep on filling the expected dimensions
    var_dimnames <- unlist(lapply(fnc$var[[namevar]][['dim']], '[[', 'name'))
    nmemb <- nltime <- NULL
    ## Sometimes CDO renames 'members' dimension to 'lev'
    old_members_dimname <- NULL
    if (('lev' %in% var_dimnames) && !(work_piece[['dimnames']][['member']] %in% var_dimnames)) {
      old_members_dimname <- work_piece[['dimnames']][['member']]
      work_piece[['dimnames']][['member']] <- 'lev'
    }
    if (work_piece[['dimnames']][['member']] %in% var_dimnames) {
      nmemb <- fnc$var[[namevar]][['dim']][[match(work_piece[['dimnames']][['member']], var_dimnames)]]$len
      expected_dims <- c(expected_dims, work_piece[['dimnames']][['member']])
    } else {
      nmemb <- 1
    }
    if (length(expected_dims) > 0) {
      dim_matches <- match(expected_dims, var_dimnames)
      if (any(is.na(dim_matches))) {
        if (!is.null(old_members_dimname)) {
          expected_dims[which(expected_dims == 'lev')] <- old_members_dimname
        }
        stop(paste("Error: the expected dimension(s)", 
                   paste(expected_dims[which(is.na(dim_matches))], collapse = ', '), 
                   "were not found in", filename))
      }
      time_dimname <- var_dimnames[-dim_matches]
    } else {
      time_dimname <- var_dimnames
    }
    if (length(time_dimname) > 0) {
      if (length(time_dimname) == 1) {
        nltime <- fnc$var[[namevar]][['dim']][[match(time_dimname, var_dimnames)]]$len
        expected_dims <- c(expected_dims, time_dimname)
        dim_matches <- match(expected_dims, var_dimnames)
      } else {
        if (!is.null(old_members_dimname)) {
          expected_dims[which(expected_dims == 'lev')] <- old_members_dimname
        }
        stop(paste("Error: the variable", namevar, 
                   "is defined over more dimensions than the expected (", 
                   paste(c(expected_dims, 'time'), collapse = ', '), 
                   "). It could also be that the members, longitude or latitude dimensions are named incorrectly. In that case, either rename the dimensions in the file or adjust Load() to recognize the actual name with the parameter 'dimnames'. See file", filename))
      }
    } else {
      nltime <- 1
    }

    # Now we must retrieve the data from the file, but only the asked indices.
    # So we build up the indices to retrieve.
    # Longitudes or latitudes have been retrieved already.
    if (explore_dims) {
      # If we're exploring the file we only want one time step from one member, 
      # to regrid it and work out the number of longitudes and latitudes.
      # We don't need more.
      members <- 1
      ltimes_list <- list(c(1))
    } else {
      # The data is arranged in the array 'tmp' with the dimensions in a 
      # common order:
      #   1) Longitudes 
      #   2) Latitudes
      #   3) Members (even if is not a file per member experiment)
      #   4) Lead-times
      if (work_piece[['is_file_per_dataset']]) {
        time_indices <- 1:nltime
        mons <- strsplit(system(paste('cdo showmon ', filein, 
                         ' 2>/dev/null'), intern = TRUE), split = ' ')
        years <- strsplit(system(paste('cdo showyear ', filein, 
                          ' 2>/dev/null'), intern = TRUE), split = ' ')
        mons <- as.numeric(mons[[1]][which(mons[[1]] != "")])
        years <- as.numeric(years[[1]][which(years[[1]] != "")])
        time_indices <- ts(time_indices, start = c(years[1], mons[1]), 
                           end = c(years[length(years)], mons[length(mons)]),
                           frequency = 12)
        ltimes_list <- list()
        for (sdate in work_piece[['startdates']]) {
          selected_time_indices <- window(time_indices, start = c(as.numeric(
                                   substr(sdate, 1, 4)), as.numeric(substr(sdate, 5, 6))), 
                                   end = c(3000, 12), frequency = 12, extend = TRUE)
          selected_time_indices <- selected_time_indices[work_piece[['leadtimes']]]
          ltimes_list <- c(ltimes_list, list(selected_time_indices))
        }
      } else {
        ltimes <- work_piece[['leadtimes']]
        #if (work_piece[['dataset_type']] == 'exp') {
          ltimes_list <- list(ltimes[which(ltimes <= nltime)])
        #}
      }
      ## TODO: Put, when reading matrices, this kind of warnings
      #  if (nmember < nmemb) {
      #    cat("Warning:
      members <- 1:work_piece[['nmember']]
      members <- members[which(members <= nmemb)]
    }

    # Now, for each list of leadtimes to load (usually only one list with all leadtimes), 
    # we'll join the indices and retrieve data
    found_disordered_dims <- FALSE
    for (ltimes in ltimes_list) {
      if (is_2d_var) {
        start <- c(min(lon_indices), min(lat_indices))
        end <- c(max(lon_indices), max(lat_indices))
        if (lonlat_subsetting_requested && remap_needed) {
          subset_indices <- list(min(lon_indices):max(lon_indices) - min(lon_indices) + 1,
                                 lat_indices - min(lat_indices) + 1)
          dim_longitudes <- ncdim_def(work_piece[['dimnames']][['lon']], "degrees_east", lon)
          dim_latitudes <- ncdim_def(work_piece[['dimnames']][['lat']], "degrees_north", lat)
          ncdf_dims <- list(dim_longitudes, dim_latitudes)
        } else {
          subset_indices <- list(lon_indices - min(lon_indices) + 1,
                                 lat_indices - min(lat_indices) + 1)
          ncdf_dims <- list()
        }
        final_dims <- c(length(subset_indices[[1]]), length(subset_indices[[2]]), 1, 1)
      } else {
        start <- end <- c()
        subset_indices <- list()
        ncdf_dims <- list()
        final_dims <- c(1, 1, 1, 1)
      }
      
      if (work_piece[['dimnames']][['member']] %in% expected_dims) {
        start <- c(start, head(members, 1))
        end <- c(end, tail(members, 1))
        subset_indices <- c(subset_indices, list(members - head(members, 1) + 1))
        dim_members <- ncdim_def(work_piece[['dimnames']][['member']], "", members)
        ncdf_dims <- c(ncdf_dims, list(dim_members))
        final_dims[3] <- length(members)
      }
      if (time_dimname %in% expected_dims) {
        if (any(!is.na(ltimes))) {
          start <- c(start, head(ltimes[which(!is.na(ltimes))], 1))
          end <- c(end, tail(ltimes[which(!is.na(ltimes))], 1))
          subset_indices <- c(subset_indices, list(ltimes - head(ltimes[which(!is.na(ltimes))], 1) + 1))
        } else {
          start <- c(start, NA)
          end <- c(end, NA)
          subset_indices <- c(subset_indices, list(ltimes))
        }
        dim_time <- ncdim_def(time_dimname, "", 1:length(ltimes), unlim = TRUE)
        ncdf_dims <- c(ncdf_dims, list(dim_time))
        final_dims[4] <- length(ltimes)
      }
      count <- end - start + 1
      start <- start[dim_matches]
      count <- count[dim_matches]
      subset_indices <- subset_indices[dim_matches]
      # Now that we have the indices to retrieve, we retrieve the data
      if (prod(final_dims) > 0) {
        tmp <- take(ncvar_get(fnc, namevar, start, count, 
                    collapse_degen = FALSE), 
                    1:length(subset_indices), subset_indices)
        # The data is regridded if it corresponds to an atmospheric variable. When
        # the chosen output type is 'areave' the data is not regridded to not 
        # waste computing time unless the user specified a common grid.
        if (is_2d_var) {
          ###if (!is.null(work_piece[['mask']]) && !(lonlat_subsetting_requested && remap_needed)) {
          ###  mask <- take(ncvar_get(fnc_mask, work_piece[['mask']][['nc_var_name']], 
          ###               start[dim_matches[1:2]], count[dim_matches[1:2]],
          ###               collapse_degen = FALSE), 1:2, subset_indices[dim_matches[1:2]])
          ###}
          if (lonlat_subsetting_requested && remap_needed) {
            filein <- tempfile(pattern = "loadRegridded", fileext = ".nc")
            filein2 <- tempfile(pattern = "loadRegridded2", fileext = ".nc")
            ncdf_var <- ncvar_def(namevar, "", ncdf_dims[dim_matches], 
                                  fnc$var[[namevar]]$missval, 
                                  prec = if (fnc$var[[namevar]]$prec == 'int') {
                                           'integer'
                                         } else {
                                           fnc$var[[namevar]]$prec
                                         })
            scale_factor <- ifelse(fnc$var[[namevar]]$hasScaleFact, fnc$var[[namevar]]$scaleFact, 1)
            add_offset <- ifelse(fnc$var[[namevar]]$hasAddOffset, fnc$var[[namevar]]$addOffset, 0)
            if (fnc$var[[namevar]]$hasScaleFact || fnc$var[[namevar]]$hasAddOffset) {
              tmp <- (tmp - add_offset) / scale_factor
            }
            #nc_close(fnc)
            fnc2 <- nc_create(filein2, list(ncdf_var))
            ncvar_put(fnc2, ncdf_var, tmp)
            if (add_offset != 0) {
              ncatt_put(fnc2, ncdf_var, 'add_offset', add_offset)
            }
            if (scale_factor != 1) {
              ncatt_put(fnc2, ncdf_var, 'scale_factor', scale_factor)
            }
            nc_close(fnc2)
            system(paste0("cdo -s -sellonlatbox,", if (lonmin > lonmax) {
                                                     "0,360,"
                                                   } else {
                                                     paste0(lonmin, ",", lonmax, ",")
                                                   }, latmin, ",", latmax,
                   " -remap", work_piece[['remap']], ",", common_grid_name, 
                   " ", filein2, " ", filein, " 2>/dev/null", sep = ""))
            file.remove(filein2)
            fnc2 <- nc_open(filein)
            sub_lon <- ncvar_get(fnc2, 'lon')
            sub_lat <- ncvar_get(fnc2, 'lat')
            ## We read the longitudes and latitudes from the file.
            ## In principle cdo should put in order the longitudes
            ## and slice them properly unless data is across greenwich
            sub_lon[which(sub_lon < 0)] <- sub_lon[which(sub_lon < 0)] + 360
            sub_lon_indices <- 1:length(sub_lon)
            if (lonmax < lonmin) {
              sub_lon_indices <- sub_lon_indices[which((sub_lon <= lonmax) | (sub_lon >= lonmin))]
            }
            sub_lat_indices <- 1:length(sub_lat)
            ## In principle cdo should put in order the latitudes
            if (sub_lat[1] < sub_lat[length(sub_lat)]) {
              sub_lat_indices <- length(sub_lat):1
            }
            final_dims[c(1, 2)] <- c(length(sub_lon_indices), length(sub_lat_indices))
            subset_indices[[dim_matches[1]]] <- sub_lon_indices
            subset_indices[[dim_matches[2]]] <- sub_lat_indices

            tmp <- take(ncvar_get(fnc2, namevar, collapse_degen = FALSE), 
                        1:length(subset_indices), subset_indices)

            if (!is.null(mask)) {
              ## We create a very simple 2d netcdf file that is then interpolated to the common
              ## grid to know what are the lons and lats of our slice of data
              mask_file <- tempfile(pattern = 'loadMask', fileext = '.nc')
              mask_file_remap <- tempfile(pattern = 'loadMask', fileext = '.nc')
              dim_longitudes <- ncdim_def(work_piece[['dimnames']][['lon']], "degrees_east", c(0, 360))
              dim_latitudes <- ncdim_def(work_piece[['dimnames']][['lat']], "degrees_north", c(-90, 90))
              ncdf_var <- ncvar_def('LSM', "", list(dim_longitudes, dim_latitudes), NA, 'double')
              fnc_mask <- nc_create(mask_file, list(ncdf_var))
              ncvar_put(fnc_mask, ncdf_var, array(rep(0, 4), dim = c(2, 2)))
              nc_close(fnc_mask)
              system(paste0("cdo -s remap", work_piece[['remap']], ",", common_grid_name, 
                     " ", mask_file, " ", mask_file_remap, " 2>/dev/null", sep = ""))
              fnc_mask <- nc_open(mask_file_remap)
              mask_lons <- ncvar_get(fnc_mask, 'lon')
              mask_lats <- ncvar_get(fnc_mask, 'lat')
              nc_close(fnc_mask)
              file.remove(mask_file, mask_file_remap)
              if ((dim(mask)[1] != common_grid_lons) || (dim(mask)[2] != common_grid_lats)) {
                stop(paste("Error: the mask of the dataset with index ", tail(work_piece[['indices']], 1), " in '", work_piece[['dataset_type']], "' is wrong. It must be on the common grid if the selected output type is 'lonlat', 'lon' or 'lat', or 'areave' and 'grid' has been specified. It must be on the grid of the corresponding dataset if the selected output type is 'areave' and no 'grid' has been specified. For more information check ?Load and see help on parameters 'grid', 'maskmod' and 'maskobs'.", sep = ""))
              }
              mask_lons[which(mask_lons < 0)] <- mask_lons[which(mask_lons < 0)] + 360
              if (lonmax >= lonmin) {
                mask_lon_indices <- which((mask_lons >= lonmin) & (mask_lons <= lonmax))
              } else {
                mask_lon_indices <- which((mask_lons >= lonmin) | (mask_lons <= lonmax))
              }
              mask_lat_indices <- which((mask_lats >= latmin) & (mask_lats <= latmax))
              if (sub_lat[1] < sub_lat[length(sub_lat)]) {
                mask_lat_indices <- mask_lat_indices[length(mask_lat_indices):1]
              }
              mask <- mask[mask_lon_indices, mask_lat_indices]
            }
            sub_lon <- sub_lon[sub_lon_indices]
            sub_lat <- sub_lat[sub_lat_indices]
            ###  nc_close(fnc_mask)
            ###  system(paste0("cdo -s -sellonlatbox,", if (lonmin > lonmax) {
            ###                                           "0,360,"
            ###                                         } else {
            ###                                           paste0(lonmin, ",", lonmax, ",")
            ###                                         }, latmin, ",", latmax,
            ###         " -remap", work_piece[['remap']], ",", common_grid_name, 
            ###This is wrong: same files  
            ###         " ", mask_file, " ", mask_file, " 2>/dev/null", sep = ""))
            ###  fnc_mask <- nc_open(mask_file) 
            ###  mask <- take(ncvar_get(fnc_mask, work_piece[['mask']][['nc_var_name']],
            ###               collapse_degen = FALSE), 1:2, subset_indices[dim_matches[1:2]])
            ###}
          }
        }
        if (!all(dim_matches == sort(dim_matches))) {
          if (!found_disordered_dims && rev(work_piece[['indices']])[2] == 1 && rev(work_piece[['indices']])[3] == 1) {
            found_disordered_dims <- TRUE
            cat(paste0("! Warning: the dimensions for the variable ", namevar, " in the files of the experiment with index ", tail(work_piece[['indices']], 1), " are not in the optimal order for loading with Load(). The optimal order would be '", paste(expected_dims, collapse = ', '), "'. One of the files of the dataset is stored in ", filename))
          }
          tmp <- aperm(tmp, dim_matches)
        }
        dim(tmp) <- final_dims
        # If we are exploring the file we don't need to process and arrange
        # the retrieved data. We only need to keep the dimension sizes.
        if (is_2d_var && lonlat_subsetting_requested && remap_needed) {
          final_lons <- sub_lon
          final_lats <- sub_lat
        } else {
          final_lons <- lon
          final_lats <- lat
        }
        if (explore_dims) {
          if (work_piece[['is_file_per_member']]) {
            ## TODO: When the exp_full_path contains asterisks and is file_per_member
            ##       members from different datasets may be accounted.
            ##       Also if one file member is missing the accounting will be wrong.
            ##       Should parse the file name and extract number of members.
            if (is_url) {
              nmemb <- NULL
            } else {
              nmemb <- length(files)
            }
          }
          dims <- list(member = nmemb, ftime = nltime, lon = final_lons, lat = final_lats)
        } else {
        # If we are not exploring, then we have to process the retrieved data
          if (is_2d_var) {
            tmp <- apply(tmp, c(3, 4), function(x) {
              # Disable of large values.
              if (!is.na(work_piece[['var_limits']][2])) {
                x[which(x > work_piece[['var_limits']][2])] <- NA
              }
              if (!is.na(work_piece[['var_limits']][1])) {
                x[which(x < work_piece[['var_limits']][1])] <- NA
              }
              if (!is.null(mask)) {
                x[which(mask < 0.5)] <- NA
              }
  
              if (output == 'areave' || output == 'lon') {
                weights <- InsertDim(cos(final_lats * pi / 180), 1, length(final_lons))
                weights[which(is.na(x))] <- NA
                if (output == 'areave') {
                  weights <- weights / mean(weights, na.rm = TRUE)
                  mean(x * weights, na.rm = TRUE) 
                } else {
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                  weights <- weights / InsertDim(MeanDims(weights, 2, narm = TRUE), 2, length(final_lats))
                  MeanDims(x * weights, 2, narm = TRUE)
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                MeanDims(x, 1, narm = TRUE)
              } else if (output == 'lonlat') {
                signif(x, 5)
              }
            })
            if (output == 'areave') {
              dim(tmp) <- c(1, 1, final_dims[3:4])
            } else if (output == 'lon') {
              dim(tmp) <- c(final_dims[1], 1, final_dims[3:4])
            } else if (output == 'lat') {
              dim(tmp) <- c(1, final_dims[c(2, 3, 4)])
            } else if (output == 'lonlat') {
              dim(tmp) <- final_dims
            }
          }
          var_data <- attach.big.matrix(work_piece[['out_pointer']])
          if (work_piece[['dims']][['member']] > 1 && nmemb > 1 && 
              work_piece[['dims']][['ftime']] > 1 && 
              nltime < work_piece[['dims']][['ftime']]) {
            work_piece[['indices']][2] <- work_piece[['indices']][2] - 1
            for (jmemb in members) {
              work_piece[['indices']][2] <- work_piece[['indices']][2] + 1
              out_position <- arrayIndex2VectorIndex(work_piece[['indices']], work_piece[['dims']])
              out_indices <- out_position:(out_position + length(tmp[, , jmemb, ]) - 1)
              var_data[out_indices] <- as.vector(tmp[, , jmemb, ])
            }
            work_piece[['indices']][2] <- work_piece[['indices']][2] - tail(members, 1) + 1
          } else {
            out_position <- arrayIndex2VectorIndex(work_piece[['indices']], work_piece[['dims']])
            out_indices <- out_position:(out_position + length(tmp) - 1)
            a <- aperm(tmp, c(1, 2, 4, 3))
            as.vector(a)
            var_data[out_indices] <- as.vector(aperm(tmp, c(1, 2, 4, 3)))
          }
          work_piece[['indices']][3] <- work_piece[['indices']][3] + 1
        }
      }
    }
    nc_close(fnc)    
    if (is_2d_var) {
      if (remap_needed) {
        array_across_gw <- FALSE
        file.remove(filein)
        ###if (!is.null(mask) && lonlat_subsetting_requested) {
        ###  file.remove(mask_file)
        ###}
      } else {
        if (first_lon_in_original_file < 0) {
          array_across_gw <- data_across_gw
        } else {
          array_across_gw <- FALSE
        }
      }
    }    
  }
  if (explore_dims) {
    list(dims = dims, is_2d_var = is_2d_var, grid = grid_name, 
         units = units, var_long_name = var_long_name, 
         data_across_gw = data_across_gw, array_across_gw = array_across_gw)
  } else {
    ###if (!silent && !is.null(progress_connection) && !is.null(work_piece[['progress_amount']])) {
    ###  foobar <- writeBin(work_piece[['progress_amount']], progress_connection)
    ###}
    if (!silent && !is.null(work_piece[['progress_amount']])) {
      message(paste0(work_piece[['progress_amount']]), appendLF = FALSE)
    }
    found_file
  }
}

.LoadSampleData <- function(var, exp = NULL, obs = NULL, sdates, 
                            nmember = NULL, nmemberobs = NULL, 
                            nleadtime = NULL, leadtimemin = 1, 
                            leadtimemax = NULL, storefreq = 'monthly', 
                            sampleperiod = 1, lonmin = 0, lonmax = 360, 
                            latmin = -90, latmax = 90, output = 'areave', 
                            method = 'conservative', grid = NULL, 
                            maskmod = vector("list", 15), 
                            maskobs = vector("list", 15), 
                            configfile = NULL, suffixexp = NULL, 
                            suffixobs = NULL, varmin = NULL, varmax = NULL, 
                            silent = FALSE, nprocs = NULL) {
  ## This function loads and selects sample data stored in sampleMap and 
  ## sampleTimeSeries and is used in the examples instead of Load() so as
  ## to avoid nco and cdo system calls and computation time in the stage 
  ## of running examples in the CHECK process on CRAN.
  selected_start_dates <- match(sdates, c('19851101', '19901101', '19951101', 
                                          '20001101', '20051101'))
  start_dates_position <- 3
  lead_times_position <- 4

  if (output == 'lonlat') {
    sampleData <- s2dv::sampleMap
    if (is.null(leadtimemax)) {
      leadtimemax <- dim(sampleData$mod)[lead_times_position]
    }
    selected_lead_times <- leadtimemin:leadtimemax

    dataOut <- sampleData
    dataOut$mod <- sampleData$mod[, , selected_start_dates, selected_lead_times, , ]
    dataOut$obs <- sampleData$obs[, , selected_start_dates, selected_lead_times, , ]
  }
  else if (output == 'areave') {
    sampleData <- s2dv::sampleTimeSeries
990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660
    if (is.null(leadtimemax)) {
      leadtimemax <- dim(sampleData$mod)[lead_times_position]
    }
    selected_lead_times <- leadtimemin:leadtimemax

    dataOut <- sampleData
    dataOut$mod <- sampleData$mod[, , selected_start_dates, selected_lead_times]
    dataOut$obs <- sampleData$obs[, , selected_start_dates, selected_lead_times]
  }

  dims_out <- dim(sampleData$mod)
  dims_out[start_dates_position] <- length(selected_start_dates)
  dims_out[lead_times_position] <- length(selected_lead_times)
  dim(dataOut$mod) <- dims_out

  dims_out <- dim(sampleData$obs)
  dims_out[start_dates_position] <- length(selected_start_dates)
  dims_out[lead_times_position] <- length(selected_lead_times)
  dim(dataOut$obs) <- dims_out

  invisible(list(mod = dataOut$mod, obs = dataOut$obs, 
                 lat = dataOut$lat, lon = dataOut$lon))
}

.ConfigGetDatasetInfo <- function(matching_entries, table_name) {
  # This function obtains the information of a dataset and variable pair,
  # applying all the entries that match in the configuration file.
  if (table_name == 'experiments') {
    id <- 'EXP'
  } else {
    id <- 'OBS'
  }
  defaults <- c(paste0('$DEFAULT_', id, '_MAIN_PATH$'), paste0('$DEFAULT_', id, '_FILE_PATH$'), '$DEFAULT_NC_VAR_NAME$', '$DEFAULT_SUFFIX$', '$DEFAULT_VAR_MIN$', '$DEFAULT_VAR_MAX$')
  info <- NULL

  for (entry in matching_entries) {
    if (is.null(info)) {
      info <- entry[-1:-2]
      info[which(info == '*')] <- defaults[which(info == '*')]
    } else {
      info[which(entry[-1:-2] != '*')] <- entry[-1:-2][which(entry[-1:-2] != '*')]
    }
  }

  info <- as.list(info)
  names(info) <- c('main_path', 'file_path', 'nc_var_name', 'suffix', 'var_min', 'var_max')  
  info
}

.ReplaceGlobExpressions <- function(path_with_globs, actual_path, 
                                    replace_values, tags_to_keep, 
                                    dataset_name, permissive) {
  # The goal of this function is to replace the shell globbing expressions in
  # a path pattern (that may contain shell globbing expressions and Load() 
  # tags) by the corresponding part of the real existing path.
  # What is done actually is to replace all the values of the tags in the 
  # actual path by the corresponding $TAG$
  #
  # It takes mainly two inputs. The path with expressions and tags, e.g.:
  #   /data/experiments/*/$EXP_NAME$/$VAR_NAME$/$VAR_NAME$_*$START_DATE$*.nc
  # and a complete known path to one of the matching files, e.g.:
  #   /data/experiments/ecearth/i00k/tos/tos_fc0-1_19901101_199011-199110.nc
  # and it returns the path pattern but without shell globbing expressions:
  #   /data/experiments/ecearth/$EXP_NAME$/$VAR_NAME$/$VAR_NAME$_fc0-1_$START_DATE$_199011-199110.nc
  #
  # To do that, it needs also as inputs the list of replace values (the 
  # association of each tag to their value).
  #
  # All the tags not present in the parameter tags_to_keep will be repalced.
  #
  # Not all cases can be resolved with the implemented algorithm. In an
  # unsolvable case a warning is given and one possible guess is returned.
  #
  # In some cases it is interesting to replace only the expressions in the
  # path to the file, but not the ones in the file name itself. To keep the
  # expressions in the file name, the parameter permissive can be set to 
  # TRUE. To replace all the expressions it can be set to FALSE.
  clean <- function(x) {
    if (nchar(x) > 0) {
      x <- gsub('\\\\', '', x)
      x <- gsub('\\^', '', x)
      x <- gsub('\\$', '', x)
      x <- unname(sapply(strsplit(x, '[',fixed = TRUE)[[1]], function(y) gsub('.*]', '.', y)))
      do.call(paste0, as.list(x))
    } else {
      x
    }
  }

  strReverse <- function(x) sapply(lapply(strsplit(x, NULL), rev), paste, collapse = "")

  if (permissive) {
    actual_path_chunks <- strsplit(actual_path, '/')[[1]]
    actual_path <- paste(actual_path_chunks[-length(actual_path_chunks)], collapse = '/')
    file_name <- tail(actual_path_chunks, 1)
    if (length(actual_path_chunks) > 1) {
      file_name <- paste0('/', file_name)
    }
    path_with_globs_chunks <- strsplit(path_with_globs, '/')[[1]]
    path_with_globs <- paste(path_with_globs_chunks[-length(path_with_globs_chunks)], 
                             collapse = '/')
    path_with_globs <- .ConfigReplaceVariablesInString(path_with_globs, replace_values)
    file_name_with_globs <- tail(path_with_globs_chunks, 1)
    if (length(path_with_globs_chunks) > 1) {
      file_name_with_globs <- paste0('/', file_name_with_globs)
    }
    right_known <- head(strsplit(file_name_with_globs, '*', fixed = TRUE)[[1]], 1)
    right_known_no_tags <- .ConfigReplaceVariablesInString(right_known, replace_values)
    path_with_globs_rx <- utils::glob2rx(paste0(path_with_globs, right_known_no_tags))
    match <- regexpr(gsub('$', '', path_with_globs_rx, fixed = TRUE), paste0(actual_path, file_name))
    if (match != 1) {
      stop("Incorrect parameters to replace glob expressions. The path with expressions does not match the actual path.")
    }
    if (attr(match, 'match.length') - nchar(right_known_no_tags) < nchar(actual_path)) {
      path_with_globs <- paste0(path_with_globs, right_known_no_tags, '*')
      file_name_with_globs <- sub(right_known, '/*', file_name_with_globs)
    } 
  }
  path_with_globs_rx <- utils::glob2rx(path_with_globs)
  values_to_replace <- c()
  tags_to_replace_starts <- c()
  tags_to_replace_ends <- c()
  give_warning <- FALSE
  for (tag in tags_to_keep) {
    matches <- gregexpr(paste0('$', tag, '$'), path_with_globs_rx, fixed = TRUE)[[1]]
    lengths <- attr(matches, 'match.length')
    if (!(length(matches) == 1 && matches[1] == -1)) {
      for (i in 1:length(matches)) {
        left <- NULL
        if (matches[i] > 1) {
          left <- .ConfigReplaceVariablesInString(substr(path_with_globs_rx, 1, matches[i] - 1), replace_values)
          left_known <- strReverse(head(strsplit(strReverse(left), strReverse('.*'), fixed = TRUE)[[1]], 1))
        }
        right <- NULL
        if ((matches[i] + lengths[i] - 1) < nchar(path_with_globs_rx)) {
          right <- .ConfigReplaceVariablesInString(substr(path_with_globs_rx, matches[i] + lengths[i], nchar(path_with_globs_rx)), replace_values)
          right_known <- head(strsplit(right, '.*', fixed = TRUE)[[1]], 1)
        }
        final_match <- NULL
        match_limits <- NULL
        if (!is.null(left)) {
          left_match <- regexpr(paste0(left, replace_values[[tag]], right_known), actual_path)
          match_len <- attr(left_match, 'match.length')
          left_match_limits <- c(left_match + match_len - 1 - nchar(clean(right_known)) - nchar(replace_values[[tag]]) + 1, 
                                 left_match + match_len - 1 - nchar(clean(right_known)))
          if (!(left_match < 1)) {
            match_limits <- left_match_limits
          }
        }
        right_match <- NULL
        if (!is.null(right)) {
          right_match <- regexpr(paste0(left_known, replace_values[[tag]], right), actual_path)
          match_len <- attr(right_match, 'match.length')
          right_match_limits <- c(right_match + nchar(clean(left_known)),  
                                  right_match + nchar(clean(left_known)) + nchar(replace_values[[tag]]) - 1)
          if (is.null(match_limits) && !(right_match < 1)) {
            match_limits <- right_match_limits
          }
        }
        if (!is.null(right_match) && !is.null(left_match)) {
          if (!identical(right_match_limits, left_match_limits)) {
            give_warning <- TRUE
          }
        }
        if (is.null(match_limits)) {
          stop("Too complex path pattern specified for ", dataset_name,
               ". Specify a simpler path pattern for this dataset.")
        }
        values_to_replace <- c(values_to_replace, tag)
        tags_to_replace_starts <- c(tags_to_replace_starts, match_limits[1])
        tags_to_replace_ends <- c(tags_to_replace_ends, match_limits[2])
      }
    }
  }

  if (length(tags_to_replace_starts) > 0) {
    reorder <- sort(tags_to_replace_starts, index.return = TRUE)
    tags_to_replace_starts <- reorder$x
    values_to_replace <- values_to_replace[reorder$ix]
    tags_to_replace_ends <- tags_to_replace_ends[reorder$ix]
    while (length(values_to_replace) > 0) {
      actual_path <- paste0(substr(actual_path, 1, head(tags_to_replace_starts, 1) - 1),
                           '$', head(values_to_replace, 1), '$',
                           substr(actual_path, head(tags_to_replace_ends, 1) + 1, nchar(actual_path)))
      extra_chars <- nchar(head(values_to_replace, 1)) + 2 - (head(tags_to_replace_ends, 1) - head(tags_to_replace_starts, 1) + 1)
      values_to_replace <- values_to_replace[-1]
      tags_to_replace_starts <- tags_to_replace_starts[-1]
      tags_to_replace_ends <- tags_to_replace_ends[-1]
      tags_to_replace_starts <- tags_to_replace_starts + extra_chars
      tags_to_replace_ends <- tags_to_replace_ends + extra_chars
    }
  }

  if (give_warning) {
    .warning(paste0("Too complex path pattern specified for ", dataset_name, 
                    ". Double check carefully the '$Files' fetched for this dataset or specify a simpler path pattern."))
  }

  if (permissive) {
    paste0(actual_path, file_name_with_globs)
  } else {
    actual_path
  }
}

.FindTagValue <- function(path_with_globs_and_tag, actual_path, tag) {
  tag <- paste0('\\$', tag, '\\$')
  path_with_globs_and_tag <- paste0('^', path_with_globs_and_tag, '$')
  parts <- strsplit(path_with_globs_and_tag, '*', fixed = TRUE)[[1]]
  parts <- as.list(parts[grep(tag, parts)])
  longest_couples <- c()
  pos_longest_couples <- c()
  found_value <- NULL
  for (i in 1:length(parts)) {
    parts[[i]] <- strsplit(parts[[i]], tag)[[1]]
    if (length(parts[[i]]) == 1) {
      parts[[i]] <- c(parts[[i]], '')
    }
    len_parts <- sapply(parts[[i]], nchar)
    len_couples <- len_parts[-length(len_parts)] + len_parts[2:length(len_parts)]
    pos_longest_couples <- c(pos_longest_couples, which.max(len_couples))
    longest_couples <- c(longest_couples, max(len_couples))
  }
  chosen_part <- which.max(longest_couples)
  parts[[chosen_part]] <- parts[[chosen_part]][pos_longest_couples[chosen_part]:(pos_longest_couples[chosen_part] + 1)]
  if (nchar(parts[[chosen_part]][1]) >= nchar(parts[[chosen_part]][2])) {
    if (nchar(parts[[chosen_part]][1]) > 0) {
      matches <- gregexpr(parts[[chosen_part]][1], actual_path)[[1]]
      if (length(matches) == 1) {
        match_left <- matches
        actual_path <- substr(actual_path, match_left + attr(match_left, 'match.length'), nchar(actual_path))
      }
    }
    if (nchar(parts[[chosen_part]][2]) > 0) {
      matches <- gregexpr(parts[[chosen_part]][2], actual_path)[[1]]
      if (length(matches) == 1) {
        match_right <- matches
        found_value <- substr(actual_path, 0, match_right - 1)
      }
    }
  } else {
    if (nchar(parts[[chosen_part]][2]) > 0) {
      matches <- gregexpr(parts[[chosen_part]][2], actual_path)[[1]]
      if (length(matches) == 1) {
        match_right <- matches
        actual_path <- substr(actual_path, 0, match_right - 1)
      }
    }
    if (nchar(parts[[chosen_part]][1]) > 0) {
      matches <- gregexpr(parts[[chosen_part]][1], actual_path)[[1]]
      if (length(matches) == 1) {
        match_left <- matches
        found_value <- substr(actual_path, match_left + attr(match_left, 'match.length'), nchar(actual_path))
      }
    }
  }
  found_value
}

.FilterUserGraphicArgs <- function(excludedArgs, ...) {
  # This function filter the extra graphical parameters passed by the user in
  # a plot function, excluding the ones that the plot function uses by default.
  # Each plot function has a different set of arguments that are not allowed to
  # be modified.
  args <- list(...)
  userArgs <- list()
  for (name in names(args)) {
      if ((name != "") & !is.element(name, excludedArgs)) {
          # If the argument has a name and it is not in the list of excluded
          # arguments, then it is added to the list that will be used
          userArgs[[name]] <- args[[name]]
      } else {
        .warning(paste0("the argument '", name, "' can not be 
        modified and the new value will be ignored"))
      }
  }
  userArgs
}

.SelectDevice <- function(fileout, width, height, units, res) {
  # This function is used in the plot functions to check the extension of the 
  # files where the graphics will be stored and select the right R device to 
  # save them.
  # If the vector of filenames ('fileout') has files with different 
  # extensions, then it will only accept the first one, changing all the rest 
  # of the filenames to use that extension.

  # We extract the extension of the filenames: '.png', '.pdf', ...
  ext <- regmatches(fileout, regexpr("\\.[a-zA-Z0-9]*$", fileout))

  if (length(ext) != 0) {
    # If there is an extension specified, select the correct device
    ## units of width and height set to accept inches
    if (ext[1] == ".png") {
      saveToFile <- function(fileout) {
        png(filename = fileout, width = width, height = height, res = res, units = units)
      }
    } else if (ext[1] == ".jpeg") {
      saveToFile <- function(fileout) {
        jpeg(filename = fileout, width = width, height = height, res = res, units = units)
      }
    } else if (ext[1] %in% c(".eps", ".ps")) {
      saveToFile <- function(fileout) {
        postscript(file = fileout, width = width, height = height)
      }
    } else if (ext[1] == ".pdf") {
      saveToFile <- function(fileout) {
        pdf(file = fileout, width = width, height = height)
      }
    } else if (ext[1] == ".svg") {
      saveToFile <- function(fileout) {
        svg(filename = fileout, width = width, height = height)
      }
    } else if (ext[1] == ".bmp") {
      saveToFile <- function(fileout) {
        bmp(filename = fileout, width = width, height = height, res = res, units = units)
      }
    } else if (ext[1] == ".tiff") {
      saveToFile <- function(fileout) {
        tiff(filename = fileout, width = width, height = height, res = res, units = units)
      }
    } else {
      .warning("file extension not supported, it will be used '.eps' by default.")
      ## In case there is only one filename
      fileout[1] <- sub("\\.[a-zA-Z0-9]*$", ".eps", fileout[1])
      ext[1] <- ".eps"
      saveToFile <- function(fileout) {
        postscript(file = fileout, width = width, height = height)
      }
    }
    # Change filenames when necessary
    if (any(ext != ext[1])) {
      .warning(paste0("some extensions of the filenames provided in 'fileout' are not ", ext[1],". The extensions are being converted to ", ext[1], "."))
      fileout <- sub("\\.[a-zA-Z0-9]*$", ext[1], fileout)
    }
  } else {
    # Default filenames when there is no specification
    .warning("there are no extensions specified in the filenames, default to '.eps'")
    fileout <- paste0(fileout, ".eps")
    saveToFile <- postscript
  }

  # return the correct function with the graphical device, and the correct 
  # filenames
  list(fun = saveToFile, files = fileout)
}

.message <- function(...) {
  # Function to use the 'message' R function with our custom settings
  # Default: new line at end of message, indent to 0, exdent to 3, 
  #  collapse to \n*
  args <- list(...)

  ## In case we need to specify message arguments
  if (!is.null(args[["appendLF"]])) {
    appendLF <- args[["appendLF"]]
  } else {
    ## Default value in message function
    appendLF <- TRUE
  } 
  if (!is.null(args[["domain"]])) {
    domain <- args[["domain"]]
  } else {
    ## Default value in message function
    domain <- NULL
  }
  args[["appendLF"]] <- NULL
  args[["domain"]] <- NULL

  ## To modify strwrap indent and exdent arguments
  if (!is.null(args[["indent"]])) {
    indent <- args[["indent"]]
  } else {
    indent <- 0
  }
  if (!is.null(args[["exdent"]])) {
    exdent <- args[["exdent"]]
  } else {
    exdent <- 3
  }
  args[["indent"]] <- NULL
  args[["exdent"]] <- NULL

  ## To modify paste collapse argument
  if (!is.null(args[["collapse"]])) {
    collapse <- args[["collapse"]]
  } else {
    collapse <- "\n*"
  }
  args[["collapse"]] <- NULL

  ## Message tag
  if (!is.null(args[["tag"]])) {
    tag <- args[["tag"]]
  } else {
    tag <- "* "
  }
  args[["tag"]] <- NULL

  message(paste0(tag, paste(strwrap(
    args, indent = indent, exdent = exdent
    ), collapse = collapse)), appendLF = appendLF, domain = domain)
}

.warning <- function(...) {
  # Function to use the 'warning' R function with our custom settings
  # Default: no call information, indent to 0, exdent to 3, 
  #  collapse to \n
  args <- list(...)

  ## In case we need to specify warning arguments
  if (!is.null(args[["call."]])) {
    call <- args[["call."]]
  } else {
    ## Default: don't show info about the call where the warning came up
    call <- FALSE
  }
  if (!is.null(args[["immediate."]])) {
    immediate <- args[["immediate."]]
  } else {
    ## Default value in warning function
    immediate <- FALSE
  }
  if (!is.null(args[["noBreaks."]])) {
    noBreaks <- args[["noBreaks."]]
  } else {
    ## Default value warning function
    noBreaks <- FALSE
  }
  if (!is.null(args[["domain"]])) {
    domain <- args[["domain"]]
  } else {
    ## Default value warning function
    domain <- NULL
  }
  args[["call."]] <- NULL
  args[["immediate."]] <- NULL
  args[["noBreaks."]] <- NULL
  args[["domain"]] <- NULL

  ## To modify strwrap indent and exdent arguments
  if (!is.null(args[["indent"]])) {
    indent <- args[["indent"]]
  } else {
    indent <- 0
  }
  if (!is.null(args[["exdent"]])) {
    exdent <- args[["exdent"]]
  } else {
    exdent <- 3
  }
  args[["indent"]] <- NULL
  args[["exdent"]] <- NULL

  ## To modify paste collapse argument
  if (!is.null(args[["collapse"]])) {
    collapse <- args[["collapse"]]
  } else {
    collapse <- "\n!"
  }
  args[["collapse"]] <- NULL

  ## Warning tag
  if (!is.null(args[["tag"]])) {
    tag <- args[["tag"]]
  } else {
    tag <- "! Warning: "
  }
  args[["tag"]] <- NULL

  warning(paste0(tag, paste(strwrap(
    args, indent = indent, exdent = exdent
    ), collapse = collapse)),  call. = call, immediate. = immediate, 
    noBreaks. = noBreaks, domain = domain)
}

.IsColor <- function(x) {
  res <- try(col2rgb(x), silent = TRUE)
  return(!"try-error" %in% class(res))
}

# This function switches to a specified figure at position (row, col) in a layout.
# This overcomes the bug in par(mfg = ...). However the mode par(new = TRUE) is 
# activated, i.e., all drawn elements will be superimposed. Additionally, after 
# using this function, the automatical pointing to the next figure in the layout
# will be spoiled: once the last figure in the layout is drawn, the pointer won't 
# move to the first figure in the layout.
# Only figures with numbers other than 0 (when creating the layout) will be
# accessible.
# Inputs: either row and col, or n and mat
.SwitchToFigure <- function(row = NULL, col = NULL, n = NULL, mat = NULL) {
  if (!is.null(n) && !is.null(mat)) {
    if (!is.numeric(n) || length(n) != 1) {
      stop("Parameter 'n' must be a single numeric value.")
    }
    n <- round(n)
    if (!is.array(mat)) {
      stop("Parameter 'mat' must be an array.")
    }
    target <- which(mat == n, arr.ind = TRUE)[1, ]
    row <- target[1]
    col <- target[2]
  } else if (!is.null(row) && !is.null(col)) {
    if (!is.numeric(row) || length(row) != 1) {
      stop("Parameter 'row' must be a single numeric value.")
    }
    row <- round(row)
    if (!is.numeric(col) || length(col) != 1) {
      stop("Parameter 'col' must be a single numeric value.")
    }
    col <- round(col)
  } else {
    stop("Either 'row' and 'col' or 'n' and 'mat' must be provided.")
  }
  next_attempt <- c(row, col)
  par(mfg = next_attempt)
  i <- 1
  layout_size <- par('mfrow')
  layout_cells <- matrix(1:prod(layout_size), layout_size[1], layout_size[2], 
                         byrow = TRUE)
  while (any((par('mfg')[1:2] != c(row, col)))) {
    next_attempt <- which(layout_cells == i, arr.ind = TRUE)[1, ]
    par(mfg = next_attempt)
    i <- i + 1
    if (i > prod(layout_size)) {
      stop("Figure not accessible.")
    }
  }
  plot(0, type = 'n', axes = FALSE, ann = FALSE)
  par(mfg = next_attempt)
}

# Function to permute arrays of non-atomic elements (e.g. POSIXct)
.aperm2 <- function(x, new_order) {
  old_dims <- dim(x)
  attr_bk <- attributes(x)
  if ('dim' %in% names(attr_bk)) {
    attr_bk[['dim']] <- NULL
  }
  if (is.numeric(x)) {
    x <- aperm(x, new_order)
  } else {
    y <- array(1:length(x), dim = dim(x))
    y <- aperm(y, new_order)
    x <- x[as.vector(y)]
  }
  dim(x) <- old_dims[new_order]
  attributes(x) <- c(attributes(x), attr_bk)
  x
}

# This function is a helper for the function .MergeArrays.
# It expects as inputs two named numeric vectors, and it extends them
# with dimensions of length 1 until an ordered common dimension
# format is reached.
# The first output is dims1 extended with 1s.
# The second output is dims2 extended with 1s.
# The third output is a merged dimension vector. If dimensions with
# the same name are found in the two inputs, and they have a different
# length, the maximum is taken.
.MergeArrayDims <- function(dims1, dims2) {
  new_dims1 <- c()
  new_dims2 <- c()
  while (length(dims1) > 0) {
    if (names(dims1)[1] %in% names(dims2)) {
      pos <- which(names(dims2) == names(dims1)[1])
      dims_to_add <- rep(1, pos - 1)
      if (length(dims_to_add) > 0) {
        names(dims_to_add) <- names(dims2[1:(pos - 1)])
      }
      new_dims1 <- c(new_dims1, dims_to_add, dims1[1])
      new_dims2 <- c(new_dims2, dims2[1:pos])
      dims1 <- dims1[-1]
      dims2 <- dims2[-c(1:pos)]
    } else {
      new_dims1 <- c(new_dims1, dims1[1])
      new_dims2 <- c(new_dims2, 1)
      names(new_dims2)[length(new_dims2)] <- names(dims1)[1]
      dims1 <- dims1[-1]
    }
  }
  if (length(dims2) > 0) {
    dims_to_add <- rep(1, length(dims2))
    names(dims_to_add) <- names(dims2)
    new_dims1 <- c(new_dims1, dims_to_add)
    new_dims2 <- c(new_dims2, dims2)
  }
  list(new_dims1, new_dims2, pmax(new_dims1, new_dims2))
}

# This function takes two named arrays and merges them, filling with
# NA where needed.
# dim(array1)
#          'b'   'c'         'e'   'f'
#           1     3           7     9
# dim(array2)
#    'a'   'b'         'd'         'f'   'g'
#     2     3           5           9     11
# dim(.MergeArrays(array1, array2, 'b'))
#    'a'   'b'   'c'   'e'   'd'   'f'   'g'
#     2     4     3     7     5     9     11
.MergeArrays <- function(array1, array2, along) {
  if (!(is.null(array1) || is.null(array2))) {
    if (!(identical(names(dim(array1)), names(dim(array2))) &&
        identical(dim(array1)[-which(names(dim(array1)) == along)],
                  dim(array2)[-which(names(dim(array2)) == along)]))) {
      new_dims <- .MergeArrayDims(dim(array1), dim(array2))
      dim(array1) <- new_dims[[1]]
      dim(array2) <- new_dims[[2]]
      for (j in 1:length(dim(array1))) {
        if (names(dim(array1))[j] != along) {
          if (dim(array1)[j] != dim(array2)[j]) {
            if (which.max(c(dim(array1)[j], dim(array2)[j])) == 1) {
              na_array_dims <- dim(array2)
              na_array_dims[j] <- dim(array1)[j] - dim(array2)[j]
              na_array <- array(dim = na_array_dims)
              array2 <- abind(array2, na_array, along = j)
              names(dim(array2)) <- names(na_array_dims)
            } else {
              na_array_dims <- dim(array1)
              na_array_dims[j] <- dim(array2)[j] - dim(array1)[j]
              na_array <- array(dim = na_array_dims)
              array1 <- abind(array1, na_array, along = j)
              names(dim(array1)) <- names(na_array_dims)
            }
          }
        }
      }
    }
    if (!(along %in% names(dim(array2)))) {
      stop("The dimension specified in 'along' is not present in the ",
           "provided arrays.")
    }
    array1 <- abind(array1, array2, along = which(names(dim(array1)) == along))
    names(dim(array1)) <- names(dim(array2))
  } else if (is.null(array1)) {
    array1 <- array2
  }
  array1
}

# only can be used in Trend(). Needs generalization or be replaced by other function.
.reorder <- function(output, time_dim, dim_names) {
  # Add dim name back
  if (is.null(dim(output))) {
    dim(output) <- c(stats = length(output))
  } else {  #is an array
    if (length(dim(output)) == 1) {
      if (!is.null(names(dim(output)))) {
        dim(output) <- c(1, dim(output))
        names(dim(output))[1] <- time_dim
      } else {
        names(dim(output)) <- time_dim
      }
    } else {  # more than one dim
      if (names(dim(output))[1] != "") {
        dim(output) <- c(1, dim(output))
        names(dim(output))[1] <- time_dim
      } else {   #regular case
        names(dim(output))[1] <- time_dim
      }
    }
  }
  # reorder
  pos <- match(dim_names, names(dim(output)))
  output <- aperm(output, pos)
  names(dim(output)) <- dim_names
  names(dim(output))[names(dim(output)) == time_dim] <- 'stats'
  return(output)
}