在coreplot ios中绘制相同Y轴的负值和正值

Question

这是我正在创建散点图：

  -(void)createScatterPlotsWithIdentifier:(NSString *)identifier color:(CPTColor *)color forGraph:(CPTGraph *)graph forXYPlotSpace:(CPTXYPlotSpace *)plotSpace{


CPTScatterPlot *scatterPlot = [[CPTScatterPlot alloc] init];
scatterPlot.dataSource = self;
scatterPlot.identifier = identifier;

//Plot a graph with in the plotspace
[plotSpace scaleToFitPlots:[NSArray arrayWithObjects:scatterPlot, nil]];

plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromUnsignedInteger(0) length:CPTDecimalFromUnsignedInteger(30)];
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromUnsignedInteger(-50) length:CPTDecimalFromUnsignedInteger(250)];

CPTMutablePlotRange *xRange = [[self getCoreplotSpace].xRange mutableCopy];
[xRange expandRangeByFactor:CPTDecimalFromCGFloat(-1)];
[self getCoreplotSpace].xRange = xRange;

CPTMutableLineStyle *scatterLineStyle = [scatterPlot.dataLineStyle mutableCopy];
scatterLineStyle.lineWidth = 1;
scatterLineStyle.lineColor = color;
scatterPlot.dataLineStyle = scatterLineStyle;

CPTMutableLineStyle *scatterSymbolLineStyle = [CPTMutableLineStyle lineStyle];
scatterSymbolLineStyle.lineColor = color;

CPTPlotSymbol *scatterSymbol = [CPTPlotSymbol ellipsePlotSymbol];
scatterSymbol.fill = [CPTFill fillWithColor:color];
scatterSymbol.lineStyle = scatterSymbolLineStyle;
scatterSymbol.size = CGSizeMake(2.0f, 2.0f);
scatterPlot.plotSymbol = scatterSymbol;

[graph addPlot:scatterPlot toPlotSpace:plotSpace];

}

像这样配置Y轴：

  NSMutableSet *yLabels = [NSMutableSet setWithCapacity:4];
NSMutableSet *yLocations = [NSMutableSet setWithCapacity:4];
NSArray *yAxisLabels = [NSArray arrayWithObjects:@"-50", @"33", @"117", @"200", nil];
NSArray *customTickLocations = [NSArray arrayWithObjects:[NSDecimalNumber numberWithUnsignedInt:-50], [NSDecimalNumber numberWithInt:33], [NSDecimalNumber numberWithInt:117], [NSDecimalNumber numberWithInt:200],nil];

for ( NSUInteger i = 0; i < [yAxisLabels count]; i++ ) {

    NSLog(@"%@",[yAxisLabels objectAtIndex:i]);
    CPTAxisLabel *label = [[CPTAxisLabel alloc] initWithText:[NSString stringWithFormat:@"%@",[yAxisLabels objectAtIndex:i]]  textStyle:axisTextStyle];
    label.tickLocation = CPTDecimalFromInteger([[customTickLocations objectAtIndex:i] integerValue]);

    label.offset = y.majorTickLength;
    if (label) {
        [yLabels addObject:label];
        [yLocations addObject:[NSString stringWithFormat:@"%d",[[customTickLocations objectAtIndex:i] integerValue]]];
    }
    label = nil;
}
y.axisLabels = yLabels;
y.majorTickLocations = [NSSet setWithArray:customTickLocations];

你能找到截图吗？ 我有以下问题。

1. 我可以设置y轴，但图表将-50设为0。
2. 在屏幕截图中，y轴未正确对齐。
3. 仅轴为粗体颜色。我怎样才能将其改为正常。
你可以帮我解决这些问题。

谢谢...



由于

Answer 1

NSString有integerValue方法，可将字符串内容解析为NSInteger。使用doubleValue方法获取浮点值。对于更复杂的数字解析任务，请使用NSScanner。

例如，

label.tickLocation = CPTDecimalFromInteger(yAxisLabels[i].integerValue);

和

[yLocations addObject:@(yAxisLabels[i].integerValue)];