使用CorePlot CPTAxisLabelingPolicyAutomatic设置显示最大y轴

Question

I want to plot a figure which have the max y axis value label showing on the label tick with CPTAxisLabelingPolicyAutomatic setting. However I haven't found any public function allow me to do that.

After checking CorePlot source code (autoGenerateMajorTickLocations method) I think I can do some workaround by using CPTDecimalDivide and CPTNiceNum. I implemented my code by increasing my plotRange in Y axis with the calculated "nice number" interval

var majorInterval = CPTDecimalDivide( Decimal(yAxisLength), 
CPTDecimalFromUnsignedInteger(5-1))
majorInterval = CPTNiceNum(majorInterval)

let interval = Int(truncating: majorInterval as NSNumber)
let number = Int(yAxisLength/interval) + 1
yAxisLength = Int(Double(number * interval))

However the CPTNiceNum is not a public method so I am wondering are there any better way to do that?

Answer 1

Call -layoutIfNeeded on the graph to make sure the axis labels are updated and then read the majorTickLocations set from the y-axis. You can find the max location value in the set easily.