javascript - chartist.js で負の数を使用する方法

Question

負の数を表示したいのですが、負の数をchartist.jsサポートしていないようです:

私のコード:

        var _4date = 'D';
        var _3date = 'C';
        var _2date = 'B';
        var _1date = 'A';

        var _4all_scores = '-100';
        var _3all_scores = '476';
        var _2all_scores = '649';
        var _1all_scores = '0';

        var _4comments_scores = '-100';
        var _3comments_scores = '20';
        var _2comments_scores = '0';
        var _1comments_scores = '0';


        var _4transactions_scores = '0';
        var _3transactions_scores = '456';
        var _2transactions_scores = '649';
        var _1transactions_scores = '0';



        var chart = new Chartist.Line('.ct-chart', {
            labels: [_1date, _2date, _3date, _4date],
            series: [
                [_1all_scores, _2all_scores, _3all_scores, _4all_scores],
                [_1comments_scores, _2comments_scores, _3comments_scores, _4comments_scores],
                [_1transactions_scores, _2transactions_scores, _3transactions_scores, _4transactions_scores]
            ]
        }, {
            low: 0,
            showArea: true,
            showPoint: false,
            fullWidth: true
        });

        chart.on('draw', function(data) {
            if(data.type === 'line' || data.type === 'area') {
                data.element.animate({
                    d: {
                        begin: 2000 * data.index,
                        dur: 2000,
                        from: data.path.clone().scale(1, 0).translate(0, data.chartRect.height()).stringify(),
                        to: data.path.clone().stringify(),
                        easing: Chartist.Svg.Easing.easeOutQuint
                    }
                });
            }
        });

https://gionkunz.github.io/chartist-js/examples.html