如何使用 CorrPlot 创建看起来像饼图的饼图？

Question

左边的图是CorePlot 图库演示中的图，右边的图是我用下面的代码创建的。我想 为了让它看起来像一个真正的圆形馅饼，我遗漏了一些东西:

-(void)configureChart {
    // 1 - Get reference to graph
    pieChartGraph = [[CPTXYGraph alloc] initWithFrame:self.pieChartgraphHostView.bounds];
    self.pieChartgraphHostView.hostedGraph = pieChartGraph;

    // 2 - Create chart
    pieChart = [[CPTPieChart alloc] init];
    pieChart.dataSource = self;
    pieChart.delegate = self;
//    pieChart.pieRadius = (self.pieChartgraphHostView.bounds.size.height * 0.7) / 2;
    pieChart.pieRadius = (self.pieChartgraphHostView.bounds.size.height * 0.7) / 2;

    pieChart.identifier = pieChartGraph.title;
    pieChart.startAngle = CPTFloat(M_PI_4);
    pieChart.sliceDirection = CPTPieDirectionClockwise;
    pieChart.borderLineStyle = [CPTLineStyle lineStyle];
    // 3 - Create gradient

    CPTGradient *overlayGradient = [[CPTGradient alloc] init];
    overlayGradient.gradientType = CPTGradientTypeRadial;
    overlayGradient = [overlayGradient addColorStop:[[CPTColor blackColor] colorWithAlphaComponent:0.0] atPosition:0.9];
    overlayGradient = [overlayGradient addColorStop:[[CPTColor blackColor] colorWithAlphaComponent:0.4] atPosition:1.0];
    pieChart.overlayFill = [CPTFill fillWithGradient:overlayGradient];
    // 4 - Add chart to graph

    [pieChartGraph addPlot:pieChart];

    pieChart.dataSource = self;

    self.dataForChart = [@[@20.0, @30.0, @60.0] mutableCopy];


    //self.dataForChart = [@[@20.0, @30.0, @60.0]mutableCopy];
}

我试图从演示库中复制代码（class 从 CorePlot example project here 调用 CorePlot）。

我做错了什么？为什么我的图表是正方形而不是圆形？

Answer 1

尝试编辑图表的半径。这就是使它成为一个圆圈的原因。要从方形视图中获取圆形，您通常会执行以下操作：

squareView.radius = view.frame.size.width/2;

你可以在饼图上试试这个：

pieChart.pieRadius = pieChart.frame.size.width/2;

顺便说一下，您将 pieChart 数据源设置为 2 倍

如何使用 CorrPlot 创建看起来像饼图的饼图？

How can I create a piechart that looks like a pie using CorePlot?

graph

core-plot

ios

pie-chart