我一直在为我的应用程序制作一组图表，并且 ScatterPlot 有一个非常具体的问题。我无法让图形的 y 轴或高度重新缩放以适应屏幕。我花了几个小时在网上搜索答案，而我最接近的是遵循 raywenderlich.com 教程。但我似乎仍然无法压缩 y 轴以使图形适合屏幕。
理想情况下，我希望图表根据输入数据动态调整大小，因为绘制的数据差异可能从几十到几百不等。
这是我用来设置图表的代码：
-(void)configureAxes{
// 1 - Create styles
CPTMutableTextStyle *axisTitleStyle = [CPTMutableTextStyle textStyle];
axisTitleStyle.color = [CPTColor whiteColor];
axisTitleStyle.fontName = @"Helvetica-Bold";
axisTitleStyle.fontSize = 12.0f;
CPTMutableLineStyle *axisLineStyle = [CPTMutableLineStyle lineStyle];
axisLineStyle.lineWidth = 2.0f;
axisLineStyle.lineColor = [CPTColor whiteColor];
CPTMutableTextStyle *axisTextStyle = [[CPTMutableTextStyle alloc] init];
axisTextStyle.color = [CPTColor whiteColor];
axisTextStyle.fontName = @"Helvetica-Bold";
axisTextStyle.fontSize = 11.0f;
CPTMutableLineStyle *tickLineStyle = [CPTMutableLineStyle lineStyle];
tickLineStyle.lineColor = [CPTColor whiteColor];
tickLineStyle.lineWidth = 2.0f;
CPTMutableLineStyle *gridLineStyle = [CPTMutableLineStyle lineStyle];
tickLineStyle.lineColor = [CPTColor blackColor];
tickLineStyle.lineWidth = 1.0f;
// 2 - Get axis set
CPTXYAxisSet *axisSet = (CPTXYAxisSet *) self.hostView.hostedGraph.axisSet;
// 3 - Configure x-axis
CPTAxis *x = axisSet.xAxis;
x.title = @"Date";
x.titleTextStyle = axisTitleStyle;
x.titleOffset = 15.0f;
x.axisLineStyle = axisLineStyle;
x.labelingPolicy = CPTAxisLabelingPolicyNone;
x.labelTextStyle = axisTextStyle;
x.majorTickLineStyle = axisLineStyle;
x.majorTickLength = 4.0f;
x.tickDirection = CPTSignNegative;
//This next line gets the number of records in the array for the date axes
CGFloat dateCount = [timesTest count];
NSMutableSet *xLabels = [NSMutableSet setWithCapacity:dateCount];
NSMutableSet *xLocations = [NSMutableSet setWithCapacity:dateCount];
//Now we build an array of dates to label the axes
NSInteger i = 0;
//for (NSString *date in [[CPDStockPriceStore sharedInstance] datesInMonth]) {
for (NSString *date in datesTest) {
CPTAxisLabel *label = [[CPTAxisLabel alloc] initWithText:date textStyle:x.labelTextStyle];
CGFloat location = i++;
label.tickLocation = CPTDecimalFromCGFloat(location);
label.offset = x.majorTickLength;
if (label) {
[xLabels addObject:label];
[xLocations addObject:[NSNumber numberWithFloat:location]];
}
}
x.axisLabels = xLabels;
x.majorTickLocations = xLocations;
// 4 - Configure y-axis
CPTAxis *y = axisSet.yAxis;
y.title = @"Time";
y.titleTextStyle = axisTitleStyle;
y.titleOffset = -40.0f;
y.axisLineStyle = axisLineStyle;
y.majorGridLineStyle = gridLineStyle;
y.labelingPolicy = CPTAxisLabelingPolicyNone;
y.labelTextStyle = axisTextStyle;
y.labelOffset = 16.0f;
y.majorTickLineStyle = axisLineStyle;
y.majorTickLength = 4.0f;
y.minorTickLength = 2.0f;
y.tickDirection = CPTSignPositive;
NSInteger majorIncrement = 100;
NSInteger minorIncrement = 50;
CGFloat yMax = 700.0f; // should determine dynamically based on max time
NSMutableSet *yLabels = [NSMutableSet set];
NSMutableSet *yMajorLocations = [NSMutableSet set];
NSMutableSet *yMinorLocations = [NSMutableSet set];
for (NSInteger j = minorIncrement; j <= yMax; j += minorIncrement) {
NSUInteger mod = j % majorIncrement;
if (mod == 0) {
CPTAxisLabel *label = [[CPTAxisLabel alloc] initWithText:[NSString stringWithFormat:@"%i", j] textStyle:y.labelTextStyle];
NSDecimal location = CPTDecimalFromInteger(j);
label.tickLocation = location;
label.offset = -y.majorTickLength - y.labelOffset;
if (label) {
[yLabels addObject:label];
}
[yMajorLocations addObject:[NSDecimalNumber decimalNumberWithDecimal:location]];
} else {
[yMinorLocations addObject:[NSDecimalNumber decimalNumberWithDecimal:CPTDecimalFromInteger(j)]];
}
}
y.axisLabels = yLabels;
y.majorTickLocations = yMajorLocations;
y.minorTickLocations = yMinorLocations;
}
#pragma mark - CPTPlotDataSource methods
-(NSUInteger)numberOfRecordsForPlot:(CPTPlot *)plot {
return [timesTest count];
}
-(NSNumber *)numberForPlot:(CPTPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index {
//NSInteger valueCount = [[[CPDStockPriceStore sharedInstance] datesInMonth] count];
NSInteger valueCount = [timesTest count];
switch (fieldEnum) {
case CPTScatterPlotFieldX:
if (index < valueCount) {
return [NSNumber numberWithUnsignedInteger:index];
}
break;
case CPTScatterPlotFieldY:
if ([plot.identifier isEqual:pbTest] == YES) {
return [pbTest objectAtIndex:index];
} else if ([plot.identifier isEqual:rollAvgTest] == YES) {
return [rollAvgTest objectAtIndex:index];
} else if ([plot.identifier isEqual:timesTest] == YES) {
return [timesTest objectAtIndex:index];
}
break;
}
return [NSDecimalNumber zero];
}
这里是我创建数组来测试图表的地方：
datesTest = [NSArray arrayWithObjects:@"4/27",
@"4/28",
@"4/29",
nil];
timesTest = [NSArray arrayWithObjects:
[NSDecimalNumber numberWithFloat:601.1],
[NSDecimalNumber numberWithFloat:614.4],
[NSDecimalNumber numberWithFloat:607.3],
nil];
pbTest = [NSArray arrayWithObjects:
[NSDecimalNumber numberWithFloat:601.1],
[NSDecimalNumber numberWithFloat:601.1],
[NSDecimalNumber numberWithFloat:601.1],
nil];
rollAvgTest = [NSArray arrayWithObjects:
[NSDecimalNumber numberWithFloat:602.1],
[NSDecimalNumber numberWithFloat:613.4],
[NSDecimalNumber numberWithFloat:605.3],
nil];
raywenderlich 项目编译并运行完美，所需的 y 轴完美缩放以适合屏幕，但我的项目没有，但我无法弄清楚我缺少什么。任何关于我哪里出错的建议将不胜感激。编辑：添加绘图配置以响应评论...
-(void)configurePlots{
// 1 - Get graph and plot space
CPTGraph *graph = self.hostView.hostedGraph;
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *) graph.defaultPlotSpace;
// 2 - Create the three plots
// FIRST PLOT is Personal Best - pbPlot
// SECOND PLOT is Rolling Average - rollAvgPlot
// THIRD PLOT is Individual swims - swimssPlot
//Plot 1 - Peronal Best
CPTScatterPlot *pbPlot = [[CPTScatterPlot alloc] init];
pbPlot.dataSource = self;
NSString *pbID = [[NSString alloc] initWithFormat:@"pbID"];
pbPlot.identifier = pbID;
CPTColor *pbColor = [CPTColor redColor];
[graph addPlot:pbPlot toPlotSpace:plotSpace];
//Plot 2 - Rolling Average
CPTScatterPlot *rollAvgPlot = [[CPTScatterPlot alloc] init];
rollAvgPlot.dataSource = self;
NSString *rollAvgID = [[NSString alloc] initWithFormat:@"rollAvgID"];
rollAvgPlot.identifier = rollAvgID;
CPTColor *rollAvgColor = [CPTColor greenColor];
[graph addPlot:rollAvgPlot toPlotSpace:plotSpace];
//Plot 3 - Actual Swim Times
CPTScatterPlot *swimsPlot = [[CPTScatterPlot alloc] init];
swimsPlot.dataSource = self;
NSString *timesID = [[NSString alloc] initWithFormat:@"timesID"];
swimsPlot.identifier = timesID;
CPTColor *swimsColor = [CPTColor blueColor];
[graph addPlot:swimsPlot toPlotSpace:plotSpace];
// 3 - Set up plot space
//[plotSpace scaleToFitPlots:[NSArray arrayWithObjects:pbPlot, rollAvgPlot, swimsPlot, nil]];
[plotSpace scaleToFitPlots:[NSArray arrayWithObjects:swimsPlot, nil]];
CPTMutablePlotRange *xRange = [plotSpace.xRange mutableCopy];
[xRange expandRangeByFactor:CPTDecimalFromCGFloat(1.1f)];
plotSpace.xRange = xRange;
CPTMutablePlotRange *yRange = [plotSpace.yRange mutableCopy];
[yRange expandRangeByFactor:CPTDecimalFromCGFloat(1.2f)];
plotSpace.yRange = yRange;
// 4 - Create styles and symbols
CPTMutableLineStyle *pbLineStyle = [pbPlot.dataLineStyle mutableCopy];
pbLineStyle.lineWidth = 2.5;
pbLineStyle.lineColor = pbColor;
pbPlot.dataLineStyle = pbLineStyle;
CPTMutableLineStyle *pbSymbolLineStyle = [CPTMutableLineStyle lineStyle];
pbSymbolLineStyle.lineColor = pbColor;
CPTPlotSymbol *pbSymbol = [CPTPlotSymbol ellipsePlotSymbol];
pbSymbol.fill = [CPTFill fillWithColor:pbColor];
pbSymbol.lineStyle = pbSymbolLineStyle;
pbSymbol.size = CGSizeMake(6.0f, 6.0f);
pbPlot.plotSymbol = pbSymbol;
CPTMutableLineStyle *rollAvgLineStyle = [rollAvgPlot.dataLineStyle mutableCopy];
rollAvgLineStyle.lineWidth = 1.0;
rollAvgLineStyle.lineColor = rollAvgColor;
rollAvgPlot.dataLineStyle = rollAvgLineStyle;
CPTMutableLineStyle *rollAvgSymbolLineStyle = [CPTMutableLineStyle lineStyle];
rollAvgSymbolLineStyle.lineColor = rollAvgColor;
CPTPlotSymbol *rollAvgSymbol = [CPTPlotSymbol starPlotSymbol];
rollAvgSymbol.fill = [CPTFill fillWithColor:rollAvgColor];
rollAvgSymbol.lineStyle = rollAvgSymbolLineStyle;
rollAvgSymbol.size = CGSizeMake(6.0f, 6.0f);
rollAvgPlot.plotSymbol = rollAvgSymbol;
CPTMutableLineStyle *swimsLineStyle = [swimsPlot.dataLineStyle mutableCopy];
swimsLineStyle.lineWidth = 2.0;
swimsLineStyle.lineColor = swimsColor;
swimsPlot.dataLineStyle = swimsLineStyle;
CPTMutableLineStyle *swimsSymbolLineStyle = [CPTMutableLineStyle lineStyle];
swimsSymbolLineStyle.lineColor = swimsColor;
CPTPlotSymbol *swimsSymbol = [CPTPlotSymbol diamondPlotSymbol];
swimsSymbol.fill = [CPTFill fillWithColor:swimsColor];
swimsSymbol.lineStyle = swimsSymbolLineStyle;
swimsSymbol.size = CGSizeMake(6.0f, 6.0f);
swimsPlot.plotSymbol = swimsSymbol;
}