BarChart won't sit on bottom of screen for some datasets, Why? How to fix?

[alexrmacleod]

I have 2 charts , a line chart and a bar chart. both have pinchZoom disabled and the barChart is overlapping the lineChart.
You can see in the images below... the barChart won't sit flush to the bottom of the screen.

However on the 1m data the bar Chart does sit flush with the bottom.

What is causing this gap below the barchart when I load new data into it? the more data I put into a barChartDataSet the more off the bar chart is from sitting on the bottom of the screen

Here is some code showing how I setup these charts.

            // Do any additional setup after loading the view, typically from a nib.
            view.backgroundColor = UIColor.whiteColor()


            //Setup linechart and add to main View
            lineChartView.frame = CGRectMake(0, LINECHART_HEADER_HEIGHT, view.frame.width, view.frame.height - LINECHART_HEADER_HEIGHT)
            lineChartView.delegate = self;
            lineChartView.descriptionText = "";
            lineChartView.noDataTextDescription = "You need to provide data for the chart.";
            lineChartView.dragEnabled = true;
            lineChartView.setScaleEnabled(true)
            //Disable pinchZoom
            lineChartView.pinchZoomEnabled = false;
            lineChartView.scaleXEnabled = false
            lineChartView.scaleYEnabled = false
            lineChartView.drawGridBackgroundEnabled = false;

            //        lineChart.autoScaleMinMaxEnabled = true
            // x-axis limit line
            let llXAxis:ChartLimitLine = ChartLimitLine(limit: 10, label: "Index 10")
            llXAxis.lineWidth = 4.0;
            llXAxis.lineDashLengths = [(10.0), (10.0), (0.0)];
            llXAxis.labelPosition = ChartLimitLine.ChartLimitLabelPosition.RightBottom
            llXAxis.valueFont = UIFont.systemFontOfSize(10)

            //[_chartView.xAxis addLimitLine:llXAxis];

            let ll1:ChartLimitLine = ChartLimitLine(limit: 130, label: "Upper Limit")
            ll1.lineWidth = 4.0;
            ll1.lineDashLengths = [5.0, 5.0];
            ll1.labelPosition = ChartLimitLine.ChartLimitLabelPosition.RightTop;
            ll1.valueFont = UIFont.systemFontOfSize(10.0);

            let ll2:ChartLimitLine = ChartLimitLine(limit: -30.0, label: "Lower Limit")
            ll2.lineWidth = 4.0;
            ll2.lineDashLengths = [5.0, 5.0];
            ll2.labelPosition = ChartLimitLine.ChartLimitLabelPosition.RightBottom;
            ll2.valueFont = UIFont.systemFontOfSize(10.0)

            let leftAxis:ChartYAxis = lineChartView.leftAxis;
            leftAxis.removeAllLimitLines()
            //        leftAxis.addLimitLine(ll1)
            //        leftAxis.addLimitLine(ll2)
            //        leftAxis.axisMaxValue = 220.0;
            //        leftAxis.axisMinValue = -50.0;
            leftAxis.gridLineDashLengths = [5.0, 5.0];
            leftAxis.drawZeroLineEnabled = false;
            leftAxis.drawLimitLinesBehindDataEnabled = true;

            lineChartView.rightAxis.enabled = false;
            lineChartView.leftAxis.enabled = false;
            lineChartView.xAxis.enabled = false;
            lineChartView.legend.enabled = false
            lineChartView.leftAxis.labelPosition = ChartYAxis.YAxisLabelPosition.InsideChart
            lineChartView.setViewPortOffsets(left: 0, top: 0, right: 0, bottom: 0)


            //Set marker for line chart
            let marker = BalloonMarker(color: UIColor.blueColor(), font: UIFont.systemFontOfSize(12), insets: UIEdgeInsetsMake(8.0, 8.0, 20.0, 8.0))
            marker.minimumSize = CGSizeMake(50, 40);
            marker.color = UIColor(red: 251/255, green: 73/255, blue: 90/255, alpha: 0.6)
            lineChartView.marker = marker

            lineChartView.legend.form = ChartLegend.ChartLegendForm.Line

            //Setup barchart and add to main View
            barChartView.frame = CGRectMake(0, view.frame.height/2, view.frame.width, view.frame.height/2)
            barChartView.delegate = self;
            barChartView.descriptionText = "";
            barChartView.noDataTextDescription = "You need to provide data for the chart.";
            barChartView.dragEnabled = true;
            barChartView.setScaleEnabled(true)
            //Disable pinchZoom
            barChartView.pinchZoomEnabled = false;
            barChartView.scaleXEnabled = false
            barChartView.scaleYEnabled = false
            barChartView.drawGridBackgroundEnabled = false;


            barChartView.rightAxis.enabled = false;
            barChartView.leftAxis.enabled = false;

            barChartView.xAxis.enabled = false;
            barChartView.legend.enabled = false
            barChartView.alpha = 0.6
            barChartView.setViewPortOffsets(left: 0, top: 0, right: 0, bottom: 0)

            informationLabel.text = ""
            //DATA request
            loadChartWithRange(range: .OneDay)

`

        //CandleChart properties:
        let candleChartDataSet = CandleChartDataSet(yVals: self.candleChartDataEntries, label: "")
        candleChartDataSet.axisDependency = ChartYAxis.AxisDependency.Left
        candleChartDataSet.setColor(UIColor(white: 80/255, alpha: 1.0))
        candleChartDataSet.highlightLineDashLengths = [5.0,2.5];
        candleChartDataSet.highlightColor = UIColor.lightGrayColor()
        candleChartDataSet.shadowColor = UIColor.darkGrayColor()
        candleChartDataSet.valueTextColor = UIColor.orangeColor()
        candleChartDataSet.drawValuesEnabled = false
        candleChartDataSet.shadowWidth = 0.7
        candleChartDataSet.decreasingColor = UIColor.redColor()
        candleChartDataSet.decreasingFilled = true;
        candleChartDataSet.increasingColor = UIColor(red: 122/255, green: 242/255, blue: 84/255, alpha: 1)
        candleChartDataSet.increasingFilled = false;
        candleChartDataSet.neutralColor = UIColor.blueColor()
        //Data to add to chart
        let candleChartData = CandleChartData()
        candleChartData.addDataSet(candleChartDataSet)

        //LineChart properties:
        let lineChartDataSet = LineChartDataSet(yVals: self.lineChartDataEntries, label: "")
        //            set1.lineDashLengths = [5.0, 2.5];
        lineChartDataSet.highlightLineDashLengths = [5.0,2.5];
        lineChartDataSet.highlightColor = UIColor.lightGrayColor()
        //Toggle color depending on price perfomrnace
        if self.lineChartDataEntries.first?.value > self.lineChartDataEntries.last?.value {
            lineChartDataSet.setColor(UIColor.redColor())
        } else if self.lineChartDataEntries.last?.value > self.lineChartDataEntries.first?.value {
            lineChartDataSet.setColor(UIColor.greenColor())
        } else if self.lineChartDataEntries.first?.value == self.lineChartDataEntries.last?.value {
            lineChartDataSet.setColor(UIColor.lightGrayColor())
        }
        lineChartDataSet.lineWidth = 1.0;
        lineChartDataSet.drawCircleHoleEnabled = false;
        lineChartDataSet.valueFont = UIFont.systemFontOfSize(9.0);
        lineChartDataSet.drawValuesEnabled = false
        let gradientColors:NSArray = [ChartColorTemplates.colorFromString("#00ff0000").CGColor,ChartColorTemplates.colorFromString("#ffff0000").CGColor]
        let gradient:CGGradientRef = CGGradientCreateWithColors(nil, gradientColors, nil)!
        lineChartDataSet.fillAlpha = 1.0;
        lineChartDataSet.fill = ChartFill.fillWithLinearGradient(gradient, angle: 90.0)
        lineChartDataSet.drawFilledEnabled = true;
        lineChartDataSet.drawCubicEnabled = false
        lineChartDataSet.drawCirclesEnabled = false

        //Data to add to chart
        let lineChartData = LineChartData(xVals: self.xVals, dataSets: [lineChartDataSet])

        //Barchart properties:
        let barChartDataSet = BarChartDataSet(yVals: self.barChartDataEntries, label: "")
        //Toggle bar color depending on price Point open and close for specfic time frame
        barChartDataSet.setColor(UIColor.greenColor())
        barChartDataSet.drawValuesEnabled = false

        //Data to add to chart
        let barChartData = BarChartData(xVals: self.xVals, dataSets: [barChartDataSet])

        //Put all the data from each chart into this combined data store
        self.lineChartView.data = lineChartData
        self.barChartView.data = barChartData
        //Redundent for combined chart view

// let data:CombinedChartData = CombinedChartData(xVals: self.xVals)
// data.lineData = lineChartData
// data.barData = barChartData
// data.candleData = candleChartData
// self.combinedChartView.data = data

        //Data configured! yay! now add chartView to mainView -_-
        self.view.addSubview(self.barChartView) //barChart under lineChart
        self.view.addSubview(self.lineChartView)

`