Remove extra chart area on Highcharts Gantt chart

Question

When adding a large number of series to the example Gantt configuration ( http://jsfiddle.net/r6emu ) additional height is added to the top and bottom of the chart area. Is there any way to prevent the additional area/lines?

Example provided here: http://jsfiddle.net/r6emu/1677/

// Define tasks
var tasks = [{
    name: 'Sleep',
    intervals: [{ // From-To pairs
        from: Date.UTC(0, 0, 0, 0),
        to: Date.UTC(0, 0, 0, 6)
    }, {
        from: Date.UTC(0, 0, 0, 22),
        to: Date.UTC(0, 0, 0, 24)
    }]
}, {
    name: 'Family time',
    intervals: [{ // From-To pairs
        from: Date.UTC(0, 0, 0, 6),
        to: Date.UTC(0, 0, 0, 16)
    }, {
        from: Date.UTC(0, 0, 0, 16),
        to: Date.UTC(0, 0, 0, 22)
    }]
}, {
    name: 'Eat',
    intervals: [{ // From-To pairs
        from: Date.UTC(0, 0, 0, 7),
        to: Date.UTC(0, 0, 0, 8),
        label: 'Breakfast'
    }, {
        from: Date.UTC(0, 0, 0, 12),
        to: Date.UTC(0, 0, 0, 12, 30)
    }, {
        from: Date.UTC(0, 0, 0, 16),
        to: Date.UTC(0, 0, 0, 17),
        label: 'Dinner'
    }, {
        from: Date.UTC(0, 0, 0, 20, 30),
        to: Date.UTC(0, 0, 0, 21)
    }]
},
[... many series removed ...]
{
    name: 'Eat',
    intervals: [{ // From-To pairs
        from: Date.UTC(0, 0, 0, 7),
        to: Date.UTC(0, 0, 0, 8),
        label: 'Breakfast'
    }, {
        from: Date.UTC(0, 0, 0, 12),
        to: Date.UTC(0, 0, 0, 12, 30)
    }, {
        from: Date.UTC(0, 0, 0, 16),
        to: Date.UTC(0, 0, 0, 17),
        label: 'Dinner'
    }, {
        from: Date.UTC(0, 0, 0, 20, 30),
        to: Date.UTC(0, 0, 0, 21)
    }]
}, {
    name: 'Work',
    intervals: [{ // From-To pairs
        from: Date.UTC(0, 0, 0, 8),
        to: Date.UTC(0, 0, 0, 16)
    }]
}];

// Define milestones
var milestones = [{
    name: 'Get to bed',
    time: Date.UTC(0, 0, 0, 22),
    task: 1,
    marker: {
        symbol: 'triangle',
        lineWidth: 1,
        lineColor: 'black',
        radius: 8
    }
}];

// re-structure the tasks into line seriesvar series = [];
var series = [];
$.each(tasks.reverse(), function(i, task) {
    var item = {
        name: task.name,
        data: []
    };
    $.each(task.intervals, function(j, interval) {
        item.data.push({
            x: interval.from,
            y: i,
            label: interval.label,
            from: interval.from,
            to: interval.to
        }, {
            x: interval.to,
            y: i,
            from: interval.from,
            to: interval.to
        });

        // add a null value between intervals
        if (task.intervals[j + 1]) {
            item.data.push(
                [(interval.to + task.intervals[j + 1].from) / 2, null]
            );
        }

    });

    series.push(item);
});

// restructure the milestones
$.each(milestones, function(i, milestone) {
    var item = Highcharts.extend(milestone, {
        data: [[
            milestone.time,
            milestone.task
        ]],
        type: 'scatter'
    });
    series.push(item);
});

console.log(series);
// create the chart
var chart = new Highcharts.Chart({

    chart: {
        renderTo: 'container'
    },

    title: {
        text: 'Daily activities'
    },

    xAxis: {
        type: 'datetime'
    },

    yAxis: {
        tickInterval: 1,
        labels: {
            formatter: function() {
                if (tasks[this.value]) {
                    return tasks[this.value].name;
                }
            }
        },
        startOnTick: false,
        endOnTick: false,
        title: {
            text: 'Activity'
        },
            minPadding: 0.2,
                maxPadding: 0.2
    },

    legend: {
        enabled: false
    },

    tooltip: {
        formatter: function() {
            return '<b>'+ tasks[this.y].name + '</b><br/>' +
                Highcharts.dateFormat('%H:%M', this.point.options.from)  +
                ' - ' + Highcharts.dateFormat('%H:%M', this.point.options.to); 
        }
    },

    plotOptions: {
        line: {
            lineWidth: 9,
            marker: {
                enabled: false
            },
            dataLabels: {
                enabled: true,
                align: 'left',
                formatter: function() {
                    return this.point.options && this.point.options.label;
                }
            }
        }
    },

    series: series

});

Answer 1

It looks like you are forcing this area by having y axis padding and the lines by having a tick interval of 1.

    yAxis: {
    tickInterval: 1,
    ..
       // minPadding: 0.2,
       //    maxPadding: 0.2

Going back to the default padding gives pretty good results, but the default of .01 may still be too much if your chart grows taller.