构建期间与核心图链接时出错

我刚刚根据教程向我的应用程序添加了一个核心绘图视图( http://www.switchonthecode.com/tutorials/using-core-plot-in-an-iphone-application )我已经将核心绘图代码放在窗口控制器的windowdidLoad方法中,用于包含cplayerHostingView的窗口。绘图代码为:

CPXYPlotSpace *plotSpace = (CPXYPlotSpace *)graph.defaultPlotSpace;
plotSpace.xRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat(-6) 
                                               length:CPDecimalFromFloat(12)];
plotSpace.yRange = [CPPlotRange plotRangeWithLocation:CPDecimalFromFloat(-5) 
                                               length:CPDecimalFromFloat(30)];

CPXYAxisSet *axisSet = (CPXYAxisSet *)graph.axisSet;

CPLineStyle *lineStyle = [CPLineStyle lineStyle];
lineStyle.lineColor = [CPColor blackColor];
lineStyle.lineWidth = 2.0f;

axisSet.xAxis.majorIntervalLength = [[NSDecimalNumber decimalNumberWithString:@"5"] decimalValue];  
axisSet.xAxis.minorTicksPerInterval = 4;
axisSet.xAxis.minorTicksPerInterval = 4;
axisSet.xAxis.majorTickLineStyle = lineStyle;
axisSet.xAxis.minorTickLineStyle = lineStyle;
axisSet.xAxis.axisLineStyle = lineStyle;
axisSet.xAxis.minorTickLength = 5.0f;
axisSet.xAxis.majorTickLength = 7.0f;
axisSet.xAxis.axisLabelOffset = 3.0f;

axisSet.yAxis.majorIntervalLength = [[NSDecimalNumber decimalNumberWithString:@"5"] decimalValue];  
axisSet.yAxis.minorTicksPerInterval = 4;
axisSet.yAxis.minorTicksPerInterval = 4;
axisSet.yAxis.majorTickLineStyle = lineStyle;
axisSet.yAxis.minorTickLineStyle = lineStyle;
axisSet.yAxis.axisLineStyle = lineStyle;
axisSet.yAxis.minorTickLength = 5.0f;
axisSet.yAxis.majorTickLength = 7.0f;
axisSet.yAxis.axisLabelOffset = 3.0f;

CPScatterPlot *xSquaredPlot = [[[CPScatterPlot alloc] 
                                initWithFrame:graph.defaultPlotSpace.bounds] autorelease];
xSquaredPlot.identifier = @"X Squared Plot";
xSquaredPlot.dataLineStyle.lineWidth = 1.0f;
xSquaredPlot.dataLineStyle.lineColor = [CPColor redColor];
xSquaredPlot.dataSource = self;
[graph addPlot:xSquaredPlot];

当我构建时,会得到以下错误:

“.objc_class_name_cpplotrange”,引用自: HistogramWindowController.o中的文本指针@uuuuobjc@uuuucls\u refs@cpplotrange

“_cpdecimafromfloat”,引用自: -histogramwindowcontroller windowdidload]在histogramwindowcontroller.o中 -histogramwindowcontroller windowdidload]在histogramwindowcontroller.o中 -histogramwindowcontroller windowdidload]在histogramwindowcontroller.o中 -histogramwindowcontroller windowdidload]在histogramwindowcontroller.o中

“.objc_class_name_cplinestyle”,引用自: HistogramWindowController.o中的文本指针@uuuuobjc@uuuucls\u refs@cplinestyle

“.objc_class_name_cpxygraph”,引用自: HistogramWindowController.o中的文本指针@uuuuobjc@uuuucls\u refs@cpxygraph

“.objc_class_name_cpscatterplot”,引用自: HistogramWindowController.o中的文本指针@uuuobjc@uuuucls\u refs@cpscatterplot

“.objc_class_name_cpplotsymbol”,引用自: HistogramWindowController.o中的文本指针@uuuobjc@uuucls\u refs@cpplotsymbol

“.objc_class_name_cpcolor”,引用自: HistogramWindowController.o中的文本指针@uuuuobjc@uuuucls\u refs@cpcolor

“.objc_class_name_cpfill”,引用自: 文本指针@uuuobjc@uuuu cls_refs@cpfill in histogramwindowcontroller.o

ld:未找到符号 Collect2:ld返回1退出状态

我从未遇到过这样的错误。有人能解释一下问题可能是什么吗?

干杯