CorePlot：将Y轴更改为3，而不是0

Question

我正在使用CorePlot 2.3在我的iOS 11.3应用程序中生成单个图形“散点图”。

如何以0以外的值启动Y轴？

Y轴当前从0.0开始并变为10.0。我想改变它，从3.0到10.0。 （数据值<3.0通常为= 0.0，可以忽略或在X轴下降到底）。

我该怎么做？

CPTXYGraph *newGraph = [[CPTXYGraph alloc] initWithFrame:CGRectZero];
CPTTheme *theme      = [CPTTheme themeNamed:kCPTDarkGradientTheme];
[newGraph applyTheme: theme];
self.graph = newGraph;

CPTGraphHostingView *hostingView = (CPTGraphHostingView *)self.view;    
hostingView.collapsesLayers = NO; 
hostingView.hostedGraph = newGraph;

CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)newGraph.defaultPlotSpace;
plotSpace.allowsUserInteraction = YES;
plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:@(-12.0) length:@(_total_frames/1.2)];
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:@(0.0) length:@(10.0)]; 
plotSpace.globalXRange = [CPTPlotRange plotRangeWithLocation:@(-15.5) length:@(_total_frames+20)];
plotSpace.globalYRange = [CPTPlotRange plotRangeWithLocation:@(-1.5) length:@(12.5)];

CPTXYAxisSet *axisSet = (CPTXYAxisSet *)newGraph.axisSet;
CPTXYAxis *xAxis                    = axisSet.xAxis;
//  .  .  .
CPTXYAxis *yAxis                    = axisSet.yAxis;
yAxis.majorIntervalLength           = @(0.5);
yAxis.minorTicksPerInterval         = 4;
yAxis.orthogonalPosition            = @(0.0);
yAxis.labelingPolicy                = CPTAxisLabelingPolicyFixedInterval; 
yAxis.labelTextStyle                = yAxisLabelTextStyle; 
yAxis.titleLocation                 = @(plotSpace.yRange.midPoint.intValue);
yAxis.title                         = @"D  I  A  M  E  T  E  R ,  m m";
yAxis.titleRotation                 = 1.57; // 90 degrees in radians
yAxis.titleOffset                   = 20.0;
yAxis.titleTextStyle                = axisTitleTextStyle;
yAxis.delegate                      = self;
yAxis.visibleRange                  = [CPTPlotRange plotRangeWithLocation:@(0.0) length:@(10.0)];

Answer 1

除非您需要对外观进行额外控制，否则请勿设置visibleRange或gridLinesRange。现在，visibleRange将y轴的可见部分限制为3.0到9.0。