title: I want to remove negative part from graph using CorePlot?
body: <p>I implement the core plot library in my application i want to remove the negative part from my graph i search a lot on google but can not find any answer. The negative values on graph is shown when i scroll down the graph and also shown i scroll to left.
  Here is my code </p>
  
  <pre><code>-(void)drawGraph{
  
      graph = [[CPTXYGraph alloc] initWithFrame:self.view.bounds];
  
      CPTTheme *theme = [CPTTheme themeNamed:kCPTDarkGradientTheme];
      [graph applyTheme:theme];
  
      hostingView1 = [[CPTGraphHostingView alloc] initWithFrame:self.view.bounds];
      hostingView1.hostedGraph = graph;
      if ([[UIScreen mainScreen] bounds].size.height == 568){
          hostingView1.frame = CGRectMake(15, 5, 290, 220);
      }
      else{
      hostingView1.frame = CGRectMake(15, 3, 290, 135);
      }
      [myGraphView addSubview:hostingView1];
      [myGraphView addSubview:lbl1];
      [myGraphView addSubview:lbl2];
  
      [lbl1 setTransform:CGAffineTransformMakeRotation(-M_PI / 2)];
      [hostingView1 release];
  
  
      graph.paddingLeft = 0;
      graph.paddingTop = 0;
      graph.paddingRight = 0;
      graph.paddingBottom = 0;
  
      graph.plotAreaFrame.paddingLeft = 35.0 ;
      graph.plotAreaFrame.paddingTop = 20.0 ;
      graph.plotAreaFrame.paddingRight = 5.0 ;
      graph.plotAreaFrame.paddingBottom = 30 ;
  
      CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)graph.defaultPlotSpace;
      plotSpace.allowsUserInteraction = YES;
  
      plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0.0) length:CPTDecimalFromFloat(50.0)];
      plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0.0) length:CPTDecimalFromFloat(10.0)];
  
      CPTXYAxisSet *axisSet = (CPTXYAxisSet *) graph.axisSet ;
      CPTXYAxis *x = axisSet.xAxis ;
      x. minorTickLineStyle = nil ;
  
      x. majorIntervalLength = CPTDecimalFromString (@"10");
  
      x. orthogonalCoordinateDecimal = CPTDecimalFromString ( @"0" );
  
      CPTXYAxis *y = axisSet.yAxis ;
  
      y. minorTickLineStyle = nil ;
  
      y. majorIntervalLength = CPTDecimalFromString ( @"2" );
  
      y. orthogonalCoordinateDecimal = CPTDecimalFromString (@"0");
  
      dataSourceLinePlot = [[[CPTScatterPlot alloc] init] autorelease];
      dataSourceLinePlot.identifier = @"Green Plot";
  
      CPTMutableLineStyle *lineStyle = [[dataSourceLinePlot.dataLineStyle mutableCopy] autorelease];
      lineStyle.lineWidth = 0.3f;
      lineStyle.lineColor = [CPTColor orangeColor];
      dataSourceLinePlot.dataLineStyle = lineStyle;
  
      dataSourceLinePlot.opacity = 0.0f;
  
      dataSourceLinePlot.dataSource = self;
      [graph addPlot:dataSourceLinePlot];
  
      CPTGradient *areaGradient = [ CPTGradient gradientWithBeginningColor :[CPTColor orangeColor] endingColor :[CPTColor colorWithComponentRed:0.55 green:0.55 blue:0.16 alpha:0.0]];
  
      areaGradient.angle = -00.0f ;
  
      CPTFill *areaGradientFill = [ CPTFill fillWithGradient :areaGradient];
  
      dataSourceLinePlot. areaFill = areaGradientFill;
      dataSourceLinePlot. areaBaseValue = CPTDecimalFromString ( @"0.0" );
      dataSourceLinePlot.interpolation = CPTScatterPlotInterpolationLinear ;
  
  
  }
  </code></pre>