regrid.py 文件源码

def extend_to_global(var, src_grid, global_grid, arctic_filler=None):
    """
    Use nearest neighbour to extend obs/source over the whole globe, including land.
    """

    # Create masked array of the correct shape.
    tmp = np.zeros((global_grid.num_levels, global_grid.num_lat_points,
                    global_grid.num_lon_points))
    new_data = np.ma.array(tmp, mask=global_grid.mask, copy=True)
    # Mask everything by default. The code below fills masked values with
    # nearest neighbour.
    new_data.mask[:] = True

    # Drop obs data into new grid at correct location
    lat_min_idx = find_nearest_index(global_grid.y_t[:, 0], np.min(src_grid.y_t[:]))
    if np.max(global_grid.y_t[:]) <= np.max(src_grid.y_t[:]):
        new_data[:, lat_min_idx:, :] = var[:]
    else:
        lat_max_idx = find_nearest_index(global_grid.y_t[:, 0], np.max(src_grid.y_t[:]))
        new_data[:, lat_min_idx:lat_max_idx+1, :] = var[:]

    # Fill in missing values on each level with nearest neighbour
    for l in range(var.shape[0]):
        ind = nd.distance_transform_edt(new_data[l, :, :].mask,
                                        return_distances=False,
                                        return_indices=True)
        tmp = new_data[l, :, :]
        tmp = tmp[tuple(ind)]
        new_data[l, :, :] = tmp[:, :]

    return new_data