foreach ( 1, 5, 7, 8, 9, 10, 11, 3, 3, 5, 5, 5, 7, 2, 2 ) {
    push( @data, $_ * ( $_ + 1 ) );
}
draw_graph( 'test1.png', @data );
@data = ( 1, 5, 7, 8, 9, 10, 11, 3, 3, 5, 5, 5, 7, 2, 2 );
draw_graph( 'test2.png', @data );