我正在使用 Core Plot 在 iOS 应用程序中进行一些绘图。我正在配置轴，并且在 X 下方和 Y 轴左侧出现奇怪的白线，如下图所示：
我的图表设置代码如下：
// 1 - Create the graph
CPTGraph *graph = [[CPTXYGraph alloc] initWithFrame:self.barHostView.bounds];
graph.plotAreaFrame.masksToBorder = NO;
self.barHostView.hostedGraph = graph;
// 2 - Configure the graph
[graph applyTheme:[CPTTheme themeNamed:kCPTPlainBlackTheme]];
graph.paddingBottom = 30.0f;
graph.paddingLeft = 30.0f;
graph.paddingTop = -1.0f;
graph.paddingRight = -5.0f;
// 3 - Set up styles
CPTMutableTextStyle *titleStyle = [CPTMutableTextStyle textStyle];
titleStyle.color = [CPTColor whiteColor];
titleStyle.fontName = @"Helvetica-Bold";
titleStyle.fontSize = 16.0f;
// 4 - Set up title
graph.title = [NSString stringWithFormat:@"Usage on %@", self.turnout];
graph.titleTextStyle = titleStyle;
graph.titlePlotAreaFrameAnchor = CPTRectAnchorTop;
graph.titleDisplacement = CGPointMake(0.0f, -16.0f);
// 5 - Set up plot space
CGFloat xMin = -1.5f;
CGFloat xMax = [self.points count] + 2;
CGFloat yMin = 0.0f;
self.yMax = [[self greatestFlowValue] floatValue] * 1.4;
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *) graph.defaultPlotSpace;
plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(xMin) length:CPTDecimalFromFloat(xMax)];
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(yMin) length:CPTDecimalFromFloat(self.yMax)];
CPTMutablePlotRange *yRange = [plotSpace.yRange mutableCopy];
[yRange expandRangeByFactor:CPTDecimalFromCGFloat(1.65f)];
plotSpace.yRange = yRange;
我或多或少地从教程中复制了它，然后对其进行了修改。在演练中，他们在轴上没有标签——他们在屏幕的左侧和底部设置了标签。
谁能解释导致这些额外行的原因以及我如何禁用它们？它们只出现在我的条形图上......我有其他使用散点图的图表没有任何类似的结果。