Start.R

    
    # do the storage work
    weights <- sapply(1:length(store_dims), 
                      function(i) prod(c(1, store_dims)[1:i]))
    part_indices_in_sub_array <- as.list(rep(TRUE, length(dim(sub_array))))
    names(part_indices_in_sub_array) <- names(dim(sub_array))
    data_array <- bigmemory::attach.big.matrix(shared_matrix_pointer)
    for (i in 1:n_parts) {
      store_indices[[largest_dim_name]] <- parts[[i]]
      # Converting array indices to vector indices
      matrix_indices <- do.call("expand.grid", store_indices)
      # Given a matrix where each row is a set of array indices of an element
      # the vector indices are computed
      matrix_indices <- 1 + colSums(t(matrix_indices - 1) * weights)
      part_indices_in_sub_array[[largest_dim_name]] <- part_indices[[i]]
      data_array[matrix_indices] <- as.vector(do.call('[',
                                                      c(list(x = sub_array), 
                                                        part_indices_in_sub_array)))
    }
    rm(data_array)
    gc()
    
    if (!is.null(work_piece[['save_metadata_in']])) {
      saveRDS(metadata, file = work_piece[['save_metadata_in']])
    }
  }
  if (!is.null(work_piece[['progress_amount']]) && !silent) {
    message(work_piece[['progress_amount']], appendLF = FALSE)
  }
  is.null(sub_array)
}