Bar height is calculated wrong

[inatu]

When I write my code like this, I find that the height of the bar is too big, and if I use the custom renderer, it just not work correctly. Any hint will be thankful.

    let chart = BarChartView()
    chart.backgroundColor = UIColor.whiteColor()

    chart.clipsToBounds = false
    chart.extraLeftOffset = 20.0
    chart.extraRightOffset = 30.0
    chart.descriptionText = ""
    chart.legend.enabled = false
    chart.pinchZoomEnabled = false
    chart.scaleYEnabled = false
    chart.scaleXEnabled = false
    chart.drawBordersEnabled = false
    chart.zoom(8.0, scaleY: 1.0, x: 0, y: 0)

    let xAxis = chart.xAxis
    xAxis.labelFont = UIFont.systemFontOfSize(10.0)
    xAxis.labelTextColor = UIColor(hex6: 0x000000, alpha: 0.87)
    xAxis.labelPosition = .Bottom
    xAxis.drawAxisLineEnabled = false
    xAxis.yOffset = 8.0
    xAxis.drawGridLinesEnabled = false


    let limitLine = ChartLimitLine(limit: 30, label: "达标\n30")
    limitLine.lineWidth = 1.0
    limitLine.lineDashLengths = [2.0, 2.0]
    limitLine.lineColor = UIColor(hex6: 0xD8D8D8)
    limitLine.labelPosition = .RightTop
    limitLine.xOffset = -30.0
    limitLine.valueFont = UIFont.systemFontOfSize(10.0)
    limitLine.valueTextColor = UIColor(hex6: 0x000000).colorWithAlphaComponent(0.54)


    let leftYAxis = chart.leftAxis
    leftYAxis.enabled = false

    let rightYAxis = chart.rightAxis
    rightYAxis.setLabelCount(0, force: true)
    rightYAxis.axisMinValue = 0
    rightYAxis.drawZeroLineEnabled = false
    rightYAxis.drawAxisLineEnabled = false
    rightYAxis.drawTopYLabelEntryEnabled = false
    rightYAxis.drawLabelsEnabled = false
    rightYAxis.addLimitLine(limitLine)

    var xVals = [String]()
    var yVals = [BarChartDataEntry]()
    for (index, point) in points.enumerate()
    {
      xVals.append(point.x)
      yVals.append(BarChartDataEntry(value: point.y, xIndex: index))
    }

    let dataSet = BarChartDataSet(yVals: yVals, label: nil)
    dataSet.setColor(UIColor(hex6: 0xF8BC1C), alpha: 1.0)
    dataSet.drawValuesEnabled = false
    dataSet.highlightEnabled = false
    dataSet.barSpace = 0.7
    let chartData = BarChartData(xVals: xVals, dataSet: dataSet)
    chart.data = chartData

    performanceDetailTimeView.chart = chart

    if timeViewDisplayed
    {
      performanceDetailTimeView.loadChart() // the chart will be added to a view, like  chartView.addSubview(chart), chart.frame = chartView.bounds

      chart.moveViewToX(CGFloat(points.count))
    }
```swift

[inatu]

for example, one point being transformed to

▿ CGRect
  ▿ origin : CGPoint
    - x : -2268.3466666666664
    - y : 211.7275390625
  ▿ size : CGSize
    - width : 14.559999999999945
    - height : 4075.3038194444398 { ... }

[liuxuan30]

well, since you mentioned a custom renderer, your should first understand how the bar is calculated and renderered and debug on your side.
The only hint I can say is, the transformer's matrix is a mess. It looks like first you should draw a normal bar chart and then try set the scale and other properties that's related to matrix.