iOS CorePlot 初始化速度极慢

Question

我正在尝试使用 CorePlot 绘制 iPhone 上传感器收集的数据，我几乎完成了它，但是 Coreplot 的初始化非常非常慢。这是我在 viewDidLoad 方法中的代码:

    CPTGraphHostingView* hostView = [[CPTGraphHostingView alloc] initWithFrame:self.coreplot.frame];
    [self.view addSubview: hostView];

    // Create a CPTGraph object and add to hostView
    graph = [[CPTXYGraph alloc] initWithFrame:hostView.bounds];
    hostView.hostedGraph = graph;

    // Get the (default) plotspace from the graph so we can set its x/y ranges
    CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *) graph.defaultPlotSpace;

    // Note that these CPTPlotRange are defined by START and LENGTH (not START and END) !!
    [plotSpace setYRange: [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat( -2000 ) length:CPTDecimalFromFloat( 4000 )]];
    [plotSpace setXRange: [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat( 0 ) length:CPTDecimalFromFloat( 100)]];
    // Create the plot (we do not define actual x/y values yet, these will be supplied by the datasource...)
    CPTScatterPlot* plot = [[CPTScatterPlot alloc] initWithFrame:CGRectZero];

    // Let's keep it simple and let this class act as datasource (therefore we implemtn <CPTPlotDataSource>)
    plot.dataSource = self;
    CPTMutableLineStyle *lineStyle = [CPTMutableLineStyle lineStyle];
    lineStyle.lineWidth = 2.0f;
    lineStyle.lineColor = [CPTColor redColor];
    plot.dataLineStyle = lineStyle;
    // Finally, add the created plot to the default plot space of the CPTGraph object we created before
    [graph addPlot:plot toPlotSpace:graph.defaultPlotSpace];
    [graph.defaultPlotSpace scaleToFitPlots:[graph allPlots]];

启动应用程序需要很长时间，但是当它完成加载时，它运行良好。有没有更快的加载方式，因为目前我无法接受。

Answer 1

更新轴标签策略和/或相关属性以减少刻度线和轴标签的数量。默认值会沿每个轴创建一个单位的刻度和标签 - 使用您的代码片段中显示的范围，创建和显示超过 6,000 个标签。