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我必須繪製多個圖形。我必須考慮一個Y值爲紅色，藍色圖形和Y2軸的綠色圖形值。我正在使用核心平臺庫......我完成了像下面的東西，並得到圖像如下圖像。但我需要爲y和y2設置不同的值。 
我沒有得到如何繪製...請幫我...使用CorePlot庫繪製多個圖形
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)self.graph.defaultPlotSpace;
plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromInt(self.xRangeMinVal) length:CPTDecimalFromInt(self.xRangeMaxVal)];
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromInt(self.yRangeMinVal) length:CPTDecimalFromInt(self.yRangeMaxVal)];
//plotSpace.allowsUserInteraction = YES;
//plotSpace.delegate = self;
// Grid line styles
CPTMutableLineStyle *majorGridLineStyle = [CPTMutableLineStyle lineStyle];
majorGridLineStyle.lineWidth = 0.75;
majorGridLineStyle.dashPattern = [NSArray arrayWithObjects:[NSNumber numberWithFloat:2.0f], nil];
majorGridLineStyle.lineColor = [[CPTColor colorWithGenericGray:0.4] colorWithAlphaComponent:0.4];
CPTMutableLineStyle *minorGridLineStyle = [CPTMutableLineStyle lineStyle];
minorGridLineStyle.lineWidth = 0.25;
minorGridLineStyle.lineColor = [[CPTColor colorWithGenericGray:0.4] colorWithAlphaComponent:0.1];
CPTMutableTextStyle *textStyle = [CPTTextStyle textStyle];
textStyle.color = [CPTColor blackColor];
textStyle.fontSize = 16.0f;
textStyle.textAlignment = CPTTextAlignmentCenter;
CPTMutableLineStyle *axisLineStyle = [CPTMutableLineStyle lineStyle];
axisLineStyle.lineWidth = 3.0;
axisLineStyle.lineCap = kCGLineCapRound;
// Axes
// Label x axis with a fixed interval policy
CPTXYAxisSet *axisSet = (CPTXYAxisSet *)self.graph.axisSet;
CPTXYAxis *x = axisSet.xAxis;
x.majorIntervalLength = CPTDecimalFromString(@"2.0");
x.orthogonalCoordinateDecimal = CPTDecimalFromString(@"0.0");
x.minorTicksPerInterval = 1;
x.majorGridLineStyle = majorGridLineStyle;
x.minorGridLineStyle = minorGridLineStyle;
//x.preferredNumberOfMajorTicks=;
x.labelingPolicy = CPTAxisLabelingPolicyAutomatic;
//x.title = [NSString stringWithFormat:@"goat"];
//x.titleOffset = 10.0;
//x.titleLocation = CPTDecimalFromString(@"0.0");
x.title = self.xLineTitle;
x.axisLineStyle = axisLineStyle;
x.titleTextStyle = textStyle;
CPTMutableLineStyle *dottedStyle=[CPTMutableLineStyle lineStyle];
x.minorGridLineStyle=dottedStyle;
// Label y with an automatic label policy.
CPTXYAxis *y = axisSet.yAxis;
y.labelingPolicy = CPTAxisLabelingPolicyAutomatic;
// y.orthogonalCoordinateDecimal = CPTDecimalFromString(@"-10.0");
y.minorTicksPerInterval = 2;
y.preferredNumberOfMajorTicks = 8;
y.majorGridLineStyle = majorGridLineStyle;
y.minorGridLineStyle = minorGridLineStyle;
//y.labelOffset = 1.0;
y.title = self.yLineTitle;
y.titleTextStyle = textStyle;
y.axisLineStyle = axisLineStyle;
y.titleRotation = M_PI * 0.5;
y.minorGridLineStyle=dottedStyle;
CPTXYPlotSpace *plotSpace1 = (CPTXYPlotSpace *)self.graph.defaultPlotSpace;
// CPTXYPlotSpace *plotSpace1 = [[[CPTXYPlotSpace alloc] init] autorelease];
plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromInt(self.xRangeMinVal) length:CPTDecimalFromInt(self.xRangeMaxVal)];
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromInt(0) length:CPTDecimalFromInt(60)];
CPTXYAxis *y2 = [[[CPTXYAxis alloc] init] autorelease];
y2.coordinate = CPTCoordinateY;
y2.plotSpace = plotSpace1;
y2.majorGridLineStyle = majorGridLineStyle;
y2.minorGridLineStyle = minorGridLineStyle;
y2.orthogonalCoordinateDecimal = CPTDecimalFromDouble(self.xRangeMaxVal);
y2.labelingPolicy = CPTAxisLabelingPolicyAutomatic;
//y2.separateLayers = NO;
y2.preferredNumberOfMajorTicks = 7;
y2.minorTicksPerInterval = 2;//
y2.tickDirection = CPTSignPositive;
y2.axisLineStyle = axisLineStyle;
//y2.majorTickLength = 6.0;
y2.majorTickLineStyle = axisLineStyle;
//y2.minorTickLength = 4.0;
y2.title = @"Y2 Axis";
//y2.titleTextStyle = axisTitleTextStyle;
y2.titleOffset = 40.0;
//graph.axisSet.axes = [NSArray arrayWithObjects:x, y, y2, nil];
self.graph.axisSet.axes = [NSArray arrayWithObjects:x, y,y2,nil];