notifyDataSetChanged() crashes with CGAffineTransformInvert: singular matrix.

[marthadog]

I have a macOS app that uses your Charts framework and I have tried 2 x versions, i.e. 3.2.2 and 3.3.0. I use the Swift package Manager to bring down updates of your framework and all works well albeit both these versions exhibit the same issue.

I have one Line Chart view with multiple currency (pairs) DataSets and mathematically derived datasSets i.e. moving averages and standard deviations. I have disabled the "legend" on the view as I have a seperate view of buttons outside of the chart that controls the Line Chart dataSets "visible" property to clutter or declutter the chart view for the user (me) as required.

All works perfectly.

However...

I have a left Y axis range from 0.0 to 1.0 for currency exchange rates of this range.

I have a right Y axis range from 0.0 to 100.0 for currency exchange rates of this range.

As it works out I have just one currency (pair) on the right Y axis.

I click on a button in my legend view and all works well: each dataSet loses or gains visibility in the chart although still resident as a DataSet within the view.

The error:

When all dataSets within the chart are set to being not visible, i.e. nothing is showing except the left Y axis, the right Y axis, and the X axis - the moment you switch on a right Y axis dataSet "visible" and call notifyDataSetChanged() to inform the chart view that its underlying data has changed - you get a number of exceptions as follows:

CGAffineTransformInvert: singular matrix.
CGAffineTransformInvert: singular matrix.
CGAffineTransformInvert: singular matrix.
CGAffineTransformInvert: singular matrix.
CGAffineTransformInvert: singular matrix.
CGAffineTransformInvert: singular matrix.

Charts environment: macOS Mojave 10.14.4
Charts version: 3.2.2 and also tried also 3.3.0
xCode version: 10.2.1
xCode Swift version: running 4.2

    /**
     * Change view dataSet visible
     */
    @IBAction func buttonStateChanged(sender: NSButton) {
        guard let data = lineChartView.data else {
            return
        }
        
        let visible: Bool = sender.state == .on
        
        let tag = sender.tag
        
        for dataSet in data.dataSets {
            if (dataSet as? NSObject).hashValue != tag {
                continue
            }
            
            dataSet.visible = visible
            
            let (count, leftYMin, leftYMax, rightYMin, rightYMax) = data.dataSets.getVisibleDataSetCount()
            
            if count != nil {
                lineChartView.leftAxis.axisMinimum = leftYMin.reduceByPercentage(1)
                lineChartView.leftAxis.axisMaximum = leftYMax.increaseByPercentage(1)
                lineChartView.rightAxis.axisMinimum = rightYMin.reduceByPercentage(1)
                lineChartView.rightAxis.axisMaximum = rightYMax.increaseByPercentage(1)
            } else {
                lineChartView.leftAxis.axisMinimum = ViewController.defaultLeftYMin // 0.0
                lineChartView.leftAxis.axisMaximum = ViewController.defaultLeftYMax // 1.0
                lineChartView.rightAxis.axisMinimum = ViewController.defaultRightYMin // 0.0
                lineChartView.rightAxis.axisMaximum = ViewController.defaultRightYMax // 100.0
            }
            
            lineChartView.resetZoom()
            lineChartView.fitScreen()
            
            lineChartView.notifyDataSetChanged()
            
            break
        }
    }

[marthadog]

Fixed: reviewed all threads within the application and looked through the Charts source code. And seperated further data work from UI work. All done. Apologise for raising the issue.