add_heatmap_track       add heatmap to a new track
add_ideogram_track      Add ideogram track
add_lines_track         add lines to a new or exsited track
add_points_track        add points to a new or exsited track
add_rect_track          add retangles to a new or exsited track
add_segments_track      add segments to a new or exsited track
add_track               Add self-defined graphics track by track
current_track           The index of current track
get_cell_meta_data      Get meta data in a cell
gtrellis_layout         Initialize genome-level Trellis layout
gtrellis_show_index     Show index on each cell
