CorePlot - 设置y轴范围以包括所有数据点 [英] CorePlot - Set y-Axis range to include all data points
问题描述
我在iOS应用程序中实现了CorePlot图形,但是我无法根据集合中的数据点动态调整y轴的大小。一些数据集的范围为10-50,而其他数据集的范围为400-500。在这两种情况下,我都希望y-origin(0)可见。
I have implemented a CorePlot graph in my iOS application, however I am unable to dynamically size the y-Axis based on the data points in the set. Some datasets range from 10-50, while others would range from 400-500. In both cases, I would like to have y-origin (0) visible.
我尝试过使用scaletofitplots方法:
I have tried using the scaletofitplots method:
[graph.defaultPlotSpace scaleToFitPlots:[graph allPlots]];
但这对图表没有影响,它们仍然显示默认的Y轴范围0到1。
but this has no effect on the graphs, they still show the default Y-Axis range of 0 to 1.
我可以改变y轴的唯一方法是通过以下方式手动完成:
The only way that I can change the y-Axis is to do it manually via this:
graph.defaultPlotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0.0f)) length:CPTDecimalFromFloat(500.0f)];
但是这对于范围较小(10-50)的图表不起作用,因为你可以想象。
however this doesn't work well for graphs with smaller ranges (10-50), as you can imagine.
是否有任何方法可以从我的数据集中检索最高y值,以便我可以手动将最大y轴设置为该值?或者有更好的选择吗?
Is there any method to retrieve the highest y-value from my dataset so that I can manually set the maximum y-Axis to that value? Or is there a better alternative?
编辑:这是我正在使用的文件:
EDIT : Here's the file I am using:
#import "TUTSimpleScatterPlot.h"
@implementation TUTSimpleScatterPlot
@synthesize hostingView = _hostingView;
@synthesize graph = _graph;
@synthesize graphData = _graphData;
-(id)initWithHostingView:(CPTGraphHostingView *)hostingView andData:(NSMutableArray *)data {
self = [super init];
if (self != nil) {
self.hostingView = hostingView;
self.graphData = data;
self.graph = nil;
}
return self;
}
-(void)initialisePlot {
if ((self.hostingView == nil) || (self.graphData == nil)) {
NSLog(@"TUTSimpleScatterPlot: Cannot Initialise plot with hosting view and data");
return;
}
if (self.graph != nil) {
NSLog(@"TUTSimpleScatterPlot: Graph Object already exists.");
}
NSDate *refDate = [NSDate date];
NSTimeInterval oneDay = 24 * 60 * 60;
CGRect frame = [self.hostingView bounds];
self.graph = [[CPTXYGraph alloc] initWithFrame:frame];
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)self.graph.defaultPlotSpace;
plotSpace.allowsUserInteraction = YES;
plotSpace.delegate = self;
self.graph.plotAreaFrame.paddingBottom = 20.0f;
self.graph.plotAreaFrame.paddingLeft = 35.0f;
self.hostingView.hostedGraph = self.graph;
CPTMutableLineStyle *lineStyle = [CPTMutableLineStyle lineStyle];
lineStyle.lineColor = [CPTColor whiteColor];
lineStyle.lineWidth = 2.0f;
CPTMutableLineStyle *lineStyleThin = [CPTMutableLineStyle lineStyle];
lineStyleThin.lineColor = [CPTColor whiteColor];
lineStyleThin.lineWidth = 1.0f;
CPTMutableTextStyle *textStyle = [CPTMutableTextStyle textStyle];
textStyle.fontName = @"HelveticaNeue-Medium";
textStyle.fontSize = 10;
textStyle.color = [CPTColor whiteColor];
CPTMutableLineStyle *plotSymbolLineStyle = [CPTMutableLineStyle lineStyle];
plotSymbolLineStyle.lineColor = [CPTColor whiteColor];
plotSymbolLineStyle.lineWidth = 1.0f;
CPTPlotSymbol *plotSymbol = [CPTPlotSymbol ellipsePlotSymbol];
plotSymbol.lineStyle = plotSymbolLineStyle;
plotSymbol.fill = [CPTFill fillWithColor:[CPTColor colorWithComponentRed:0.4 green:0.6 blue:0.8 alpha:1.0]];
plotSymbol.size = CGSizeMake(8.0, 8.0);
CPTScatterPlot *plot = [[CPTScatterPlot alloc] init];
plot.dataSource = self;
plot.identifier = @"mainPlot";
[plotSpace scaleToFitPlots:[graph allPlots]];
CPTMutablePlotRange *yRange = [plotSpace.yRange mutableCopy];
[yRange expandRangeByFactor:CPTDecimalFromDouble(615)];
plotSpace.yRange = yRange;
plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(oneDay - (oneDay * 6.3f)) length:CPTDecimalFromFloat(oneDay * 6.6f)];
plotSpace.allowsUserInteraction = YES;
CPTPlotRange *globalYRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(0.0f) length:CPTDecimalFromDouble(615.0f)];
plotSpace.globalYRange = globalYRange;
// Modify the graph's axis with a label, line style, etc
CPTXYAxisSet *axisSet = (CPTXYAxisSet *)self.graph.axisSet;
axisSet.xAxis.axisConstraints = [CPTConstraints constraintWithLowerOffset:0.0];
axisSet.xAxis.axisLineStyle = lineStyle;
axisSet.xAxis.majorTickLineStyle = lineStyle;
axisSet.xAxis.labelTextStyle = textStyle;
axisSet.xAxis.labelOffset = 1.0f;
axisSet.xAxis.majorIntervalLength = CPTDecimalFromFloat(oneDay*1);
axisSet.xAxis.orthogonalCoordinateDecimal = CPTDecimalFromString(@"0.0");
axisSet.xAxis.minorTicksPerInterval = 0;
axisSet.xAxis.majorTickLength = 0.0f;
axisSet.xAxis.majorGridLineStyle = majorGridLineStyle;
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"dd MMM"];
CPTTimeFormatter *timeFormatter = [[CPTTimeFormatter alloc] initWithDateFormatter:dateFormatter];
timeFormatter.referenceDate = refDate;
axisSet.xAxis.labelFormatter = timeFormatter;
axisSet.yAxis.axisLineStyle = lineStyle;
axisSet.yAxis.majorTickLineStyle = lineStyle;
axisSet.yAxis.minorTickLineStyle = lineStyleThin;
axisSet.yAxis.labelTextStyle = textStyle;
axisSet.yAxis.labelOffset = 3.0f;
axisSet.yAxis.majorIntervalLength = CPTDecimalFromString(@"50.0");
axisSet.yAxis.minorTicksPerInterval = 1;
axisSet.yAxis.minorTickLength = 3.0;
axisSet.yAxis.majorTickLength = 5.0;
axisSet.yAxis.orthogonalCoordinateDecimal = CPTDecimalFromFloat(0);
axisSet.yAxis.majorGridLineStyle = majorGridLineStyle;
axisSet.yAxis.axisConstraints = [CPTConstraints constraintWithLowerOffset:0.0];
CPTMutableLineStyle *theLineStyle = [CPTMutableLineStyle lineStyle];
theLineStyle.lineColor = [CPTColor colorWithComponentRed:0.3 green:0.6 blue:0.9 alpha:1.0];
theLineStyle.lineWidth = 2.0f;
plot.dataLineStyle = theLineStyle;
plot.plotSymbol = plotSymbol;
[self.graph addPlot:plot];
}
推荐答案
它看起来就像你正确使用 -scaleToFitPlots:
一样。如果需要,此方法将更新绘图数据。在调用数据源之前,请确保数据源可以使用正确的数据。
It looks like you're using -scaleToFitPlots:
correctly. This method will update the plot data if needed. Make sure the proper data is available to the datasource before you call it.
根据新代码进行编辑:
-scaleToFitPlots:
。因此 -allPlots
数组为空,没有可扩展的内容。在构建绘图后移动缩放操作并将其添加到图形中。
-scaleToFitPlots:
is being called before you add the plot to the graph. Therefore the -allPlots
array is empty and there is nothing to scale. Move the scaling operation after the plot is built and added to the graph.
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