我在显示正确的绘图时遇到问题。我使用了 RealTimePlot 中的一些代码(http://code.google.com/p/core-plot/source/browse/examples/CorePlotGallery/src/plots/RealTimePlot.m)。不知道为什么剧情反转了。有一张照片显示了这个问题。
- (void)viewDidLoad
{
[super viewDidLoad];
[self generateDataSamples];
CPTGraphHostingView *hostingView = [[[CPTGraphHostingView alloc] initWithFrame:self.view.bounds] autorelease];
[self.view addSubview:hostingView];
graph = [[CPTXYGraph alloc] initWithFrame:self.view.bounds];
hostingView.hostedGraph = graph;
CPTTheme *theme = [CPTTheme themeNamed:kCPTSlateTheme];
[graph applyTheme:theme];
graph.plotAreaFrame.paddingTop = 15;
graph.plotAreaFrame.paddingRight = 40;
graph.plotAreaFrame.paddingBottom = 15;
graph.plotAreaFrame.paddingLeft = 55;
// Grid line styles
CPTMutableLineStyle *majorGridLineStyle = [CPTMutableLineStyle lineStyle];
majorGridLineStyle.lineWidth = 0.75;
majorGridLineStyle.lineColor = [[CPTColor colorWithGenericGray:0.2] colorWithAlphaComponent:0.75];
CPTMutableLineStyle *minorGridLineStyle = [CPTMutableLineStyle lineStyle];
minorGridLineStyle.lineWidth = 0.25;
minorGridLineStyle.lineColor = [[CPTColor whiteColor] colorWithAlphaComponent:0.1];
// Axes
// X axis
CPTXYAxisSet *axisSet = (CPTXYAxisSet *)graph.axisSet;
CPTXYAxis *x = axisSet.xAxis;
x.labelingPolicy = CPTAxisLabelingPolicyAutomatic;
x.orthogonalCoordinateDecimal = CPTDecimalFromUnsignedInteger(0);
x.majorGridLineStyle = majorGridLineStyle;
x.minorGridLineStyle = minorGridLineStyle;
x.minorTicksPerInterval = 9;
x.title = @"X Axis";
x.titleOffset = 35.0;
NSNumberFormatter *labelFormatter = [[NSNumberFormatter alloc] init];
labelFormatter.numberStyle = NSNumberFormatterNoStyle;
x.labelFormatter = labelFormatter;
[labelFormatter release];
// Y axis
CPTXYAxis *y = axisSet.yAxis;
y.labelingPolicy = CPTAxisLabelingPolicyAutomatic;
y.orthogonalCoordinateDecimal = CPTDecimalFromUnsignedInteger(0);
y.majorGridLineStyle = majorGridLineStyle;
y.minorGridLineStyle = minorGridLineStyle;
y.minorTicksPerInterval = 3;
y.labelOffset = 5.0;
y.title = @"Y Axis";
y.titleOffset = 30.0;
y.axisConstraints = [CPTConstraints constraintWithLowerOffset:0.0];
// Rotate the labels by 45 degrees, just to show it can be done.
//x.labelRotation = M_PI * 0.25;
// Create the plot
CPTScatterPlot *dataSourceLinePlot = [[[CPTScatterPlot alloc] init] autorelease];
dataSourceLinePlot.identifier = kPlotIdentifier;
dataSourceLinePlot.cachePrecision = CPTPlotCachePrecisionDouble;
CPTMutableLineStyle *lineStyle = [[dataSourceLinePlot.dataLineStyle mutableCopy] autorelease];
lineStyle.lineWidth = 3.0;
lineStyle.lineColor = [CPTColor greenColor];
dataSourceLinePlot.dataLineStyle = lineStyle;
dataSourceLinePlot.dataSource = self;
[graph addPlot:dataSourceLinePlot];
// Plot space
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)graph.defaultPlotSpace;
plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromUnsignedInteger(0) length:CPTDecimalFromUnsignedInteger(kMaxDataPoints - 1)];
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromUnsignedInteger(0) length:CPTDecimalFromUnsignedInteger(250)];
}