how to align the bar vertical center ?

[y01689]

my method now is below ， is there a better solution ？

` var myvalues = [[10,-10],[8,-8],[7,-7],[4,-4],[1,-1],[6,-6],[11,-11],
[10,-10],[8,-8],[7,-7],[4,-4],[1,-1],[6,-6],[11,-11],
[10,-10],[8,-8],[7,-7],[4,-4],[1,-1],[6,-6],[11,-11],
[10,-10],[8,-8],[7,-7],[4,-4],[1,-1],[6,-6],[11,-11],
[10,-10],[8,-8],[7,-7],[4,-4],[1,-1],[6,-6],[11,-11]];
//var myvalues = [10,4,5,9,4,7,1]
// $('.dynamicsparkline').sparkline(myvalues);

    /* The second argument gives options such as chart type */
    $('.dynamicbar').sparkline(myvalues, {
        type: 'bar', 
        lineColor:false,
        barColor: 'green',
        stackedBarColor:['green','green'],
        tooltipFormatter: function(value){
            console.log(value)
            return Math.abs(value); 
        }
    } );`