title: Core-plot bargraph with duplicated legend
body: <p>I am working with the core-plot framework to create a bar graph with a legend. It all works except that the legend is duplicating the the columns in each section of the bar graph (Please see attached screen shot). </p>
  
  <p><img src="https://i.stack.imgur.com/Dm3P9.png" alt="enter image description here"></p>
  
  <p>I have looked through the core-plot class reference and was not able to find anything to fix this problem. I have tried to set the CPTLegend properties numberOfColumns to 1 and the numberOfRows to 3 and that made the legend display the appropriate amount of items in the legend, but the data it was displaying was not correct.</p>
  
  <p><img src="https://i.stack.imgur.com/fEkes.png" alt="enter image description here"> <img src="https://i.stack.imgur.com/K5GnP.png" alt="enter image description here"></p>
  
  <p>Below is the code I'm using to build the bar graph. Do you all have any suggestions how I can fix this issue? I am assuming this is not so much a bug with core-plot but a limitation of the legend and am hoping there is a workaround.</p>
  
  <pre><code>// Create barChart from theme
  barChart = [[CPTXYGraph alloc] initWithFrame:CGRectZero];
  CPTTheme *theme = [CPTTheme themeNamed:kCPTDarkGradientTheme];
  [barChart applyTheme:theme];
  chartView.hostedGraph = barChart;
  barChart.plotAreaFrame.masksToBorder = NO;
  
  barChart.paddingLeft = 60.0;
  barChart.paddingTop = 10.0;
  barChart.paddingRight = 0.0;
  barChart.paddingBottom = 30.0;
  
  //find max y
  int maxY = 0;
  NSMutableArray *maxDrillDownData = [chartData.drillDownData objectForKey:DRILLDOWN_EQUIPMENT_ALL_TYPE];
  for (NSMutableArray *dataArray in maxDrillDownData) {
      maxY = dataArray.count&gt;maxY?dataArray.count:maxY;
  }
  
  //add buffer
  maxY = maxY+100;
  
  // Add plot space for horizontal bar charts
  CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)barChart.defaultPlotSpace;
  plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0.0f) length:CPTDecimalFromInt(maxY)];
  plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0.0f) length:CPTDecimalFromFloat(3.25)];
  
  CPTXYAxisSet *axisSet = (CPTXYAxisSet *)barChart.axisSet;
  CPTXYAxis *x = axisSet.xAxis;
  x.axisLineStyle = nil;
  x.majorTickLineStyle = nil;
  x.minorTickLineStyle = nil;
  x.majorIntervalLength = CPTDecimalFromString(@"1");
  x.orthogonalCoordinateDecimal = CPTDecimalFromString(@"0");
  x.titleLocation = CPTDecimalFromFloat(7.5f);
  x.titleOffset = 55.0f;
  x.labelOffset = 2.0;
  
  // Define some custom labels for the data elements
  x.labelRotation = M_PI/4;
  x.labelingPolicy = CPTAxisLabelingPolicyNone;
  NSArray *customTickLocations = [NSArray arrayWithObjects:[NSDecimalNumber numberWithFloat:0.5], [NSDecimalNumber numberWithFloat:1.5], [NSDecimalNumber numberWithFloat:2.5], nil];
  NSArray *xAxisLabels = (NSMutableArray *)[chartData.labels objectForKey:LABELS_EQUIPMENT_TYPE];
  NSUInteger labelLocation = 0;
  NSMutableArray *customLabels = [NSMutableArray arrayWithCapacity:[xAxisLabels count]];
  for (NSNumber *tickLocation in customTickLocations) {
      CPTAxisLabel *newLabel = [[CPTAxisLabel alloc] initWithText: [xAxisLabels objectAtIndex:labelLocation++] textStyle:x.labelTextStyle];
      newLabel.tickLocation = [tickLocation decimalValue];
      newLabel.offset = x.labelOffset;
      [customLabels addObject:newLabel];
      //[newLabel release];
  }
  
  x.axisLabels =  [NSSet setWithArray:customLabels];
  
  CPTXYAxis *y = axisSet.yAxis;
  y.axisLineStyle = nil;
  y.majorTickLineStyle = nil;
  y.minorTickLineStyle = nil;
  y.majorIntervalLength = CPTDecimalFromString(@"50");
  y.orthogonalCoordinateDecimal = CPTDecimalFromString(@"0");
  y.title = (NSString *)[chartData.labels objectForKey:LABELS_Y_AXIS];
  y.titleOffset = 45.0f;
  y.titleLocation = CPTDecimalFromFloat(150.0f);
  
  //identifiers
  NSMutableArray *identifiers = (NSMutableArray *)[chartData.identifiers objectForKey:IDENTIFIER_EQUIPMENT_TYPE];
  
  // First bar plot
  CPTBarPlot *barPlot = [CPTBarPlot tubularBarPlotWithColor:[CPTColor darkGrayColor] horizontalBars:NO];
  barPlot.baseValue = CPTDecimalFromString(@"0");
  barPlot.dataSource = self;
  barPlot.barOffset = CPTDecimalFromFloat(-0.6f);
  barPlot.barWidth = CPTDecimalFromFloat(.5);
  barPlot.delegate = self;
  barPlot.identifier = (NSString *)[identifiers objectAtIndex:0];
  [barChart addPlot:barPlot toPlotSpace:plotSpace];
  
  NSLog(@"barPlot.identifier: %@", barPlot.identifier);
  
  // Second bar plot
  barPlot = [CPTBarPlot tubularBarPlotWithColor:[CPTColor blueColor] horizontalBars:NO];
  barPlot.dataSource = self;
  barPlot.barOffset = CPTDecimalFromFloat(-0.4f);
  barPlot.barWidth = CPTDecimalFromFloat(.5);
  barPlot.baseValue = CPTDecimalFromString(@"0");
  barPlot.identifier = (NSString *)[identifiers objectAtIndex:1];
  barPlot.delegate = self;
  [barChart addPlot:barPlot toPlotSpace:plotSpace];
  
  NSLog(@"barPlot.identifier: %@", barPlot.identifier);
  
  //third bar plot
  barPlot = [CPTBarPlot tubularBarPlotWithColor:[CPTColor redColor] horizontalBars:NO];
  barPlot.dataSource = self;
  barPlot.barOffset = CPTDecimalFromFloat(-0.2f);
  barPlot.barWidth = CPTDecimalFromFloat(.5);
  barPlot.baseValue = CPTDecimalFromString(@"0");
  barPlot.identifier = (NSString *)[identifiers objectAtIndex:2];
  barPlot.delegate = self;
  [barChart addPlot:barPlot toPlotSpace:plotSpace];
  
  NSLog(@"barPlot.identifier: %@", barPlot.identifier);
  
  // Add legend
  CPTLegend *theLegend = [CPTLegend legendWithGraph:barChart];
  theLegend.numberOfColumns = 3;
  theLegend.numberOfRows = 1;
  theLegend.fill = [CPTFill fillWithColor:[CPTColor whiteColor]];
  theLegend.borderLineStyle = [CPTLineStyle lineStyle];
  theLegend.cornerRadius = 5.0;
  
  barChart.legend = theLegend;
  barChart.legendAnchor = CPTRectAnchorTopRight;
  barChart.legendDisplacement = CGPointMake(-10.0f, -20.0f);
  </code></pre>
  
  <p>Thanks for the help!</p>