SimpleView Based app with id initWithFrame Not working

I have app to create a graph i have created a view based app and then add the code for creating graph in it but it does not disply the graph. If use same code to create a separate UIView then it works other wise not

   #import <UIKit/UIKit.h>
   #import "ECGraph.h"
   #import "ECGraphItem.h"
  @class GraphsViewController;
  @interface Display : UIView {
 
 NSArray *percentages;
 
 int myY;
 ECGraph *graph;
 ECGraphItem *item1;
 ECGraphItem *item2;
 
 
    }
   @property(nonatomic,retain)NSArray*percentages;
 
  -(void) setPercentageArray:(NSArray*) array;
 
  @end
 
 
  #import "Display.h"
  #import "ECGraph.h"
  @implementation Display
  @synthesize percentages;
 
 - (id)initWithFrame:(CGRect)frame {
 
 self = [super initWithFrame:frame];
 if (self) {
     // Initialization code.
 }
 return self;
 }
 
 
 - (void)drawRect:(CGRect)rect {
 
 
 CGContextRef _context = UIGraphicsGetCurrentContext();
 
 
 
 graph = [[ECGraph alloc] initWithFrame:CGRectMake(500,-320,320, 200) withContext:_context isPortrait:NO];
 
 
 item1 = [[ECGraphItem alloc] init];
 
 item2 = [[ECGraphItem alloc] init];
 /*
 ECGraphItem *item1 = [[ECGraphItem alloc] init];
 
 ECGraphItem *item2 = [[ECGraphItem alloc] init];*/
 
 item1.isPercentage = YES;
 
 
 
 item1.yValue=myY;
 
 
 
 
 item1.width = 35;
 item1.name = @"item1";
 
 item2.isPercentage = YES;
 item2.yValue =17;
 
 item2.width = 35; 
 item2.name = @"item2";
 
 
 
 [graph setXaxisTitle:@"name"];
 [graph setYaxisTitle:@"Percentage"];
 [graph setGraphicTitle:@"Histogram"];
 [graph setDelegate:self];
 [graph setBackgroundColor:[UIColor colorWithRed:220/255.0 green:220/255.0 blue:220/255.0 alpha:1]];
 
 
 
 NSArray *items = [[NSArray alloc] initWithObjects:item1,item2,nil];
 
 
 [graph drawHistogramWithItems:items lineWidth:2 color:[UIColor blackColor]];
 
 
 
 
 }
 

I am adding this view in GraphsViewController but its not showing anything

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.

 - (void)viewDidLoad {
 [super viewDidLoad];
 
 [self createGraph];
 
 
 
 percentages = [NSArray arrayWithObjects:@"80",@"17", nil];
 
 display = [[Display alloc] init];
 
 [self.view addSubview:display];
 
 [display setPercentageArray:percentages];
 
 }
 

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