View Not Showing Up in iPhone App
===

I have 4 files, BarPlot.h and BarPlot.m, BarPlotViewController.h and BarPlotViewController.m
and my(probably very straight forward to you guys)is I cant get the BarplotViewController to display my graph.

I've made sure that the correct view controller is being called in the storyboard.

I've gone over the code multiple times but I just cant figure out why the view is not showing up when I run the app in simulator.. 

I have included the files below.

Any and all help is greatly appreciated.


BarPlotViewController.h

    #import <UIKit/UIKit.h>
    #import "CorePlot-CocoaTouch.h"
    #import "BarPlot.h"

    @interface BarPlotViewController : UIViewController {
        CPTGraphHostingView *_graphHostingView;
    }

    @property (nonatomic, retain) BarPlot *barPlot;

    @end


BarPlotViewController.m


    #import "BarPlotViewController.h"

    @implementation BarPlotViewController
    @synthesize barPlot = _barPlot;


    - (void)viewWillAppear:(BOOL)animated
    {   
        self.barPlot = [[BarPlot alloc] initWithHostingView:_graphHostingView];
        [self.barPlot generateBarPlot];
    }

    @end


BarPlot.h

    #import <UIKit/UIKit.h>
    #import "CorePlot-CocoaTouch.h"

    @interface BarPlot : UIViewController <CPTBarPlotDataSource, CPTBarPlotDelegate> {
        CPTGraphHostingView *_hostingView;	
	CPTXYGraph *_graph;
    }

    @property (nonatomic, retain) NSMutableArray *data;
    @property (nonatomic, retain) CPTGraphHostingView *hostingView;
    @property (nonatomic, retain) CPTXYGraph *graph;


    // Methods to create this object and attach it to it's hosting view.
    -(id)initWithHostingView:(CPTGraphHostingView *)hostingView;


    // Generate the bar plot
    - (void) generateBarPlot;

    @end


BarPlot.m

    #import "BarPlot.h"

    @implementation BarPlot

    #define BAR_POSITION @"POSITION"
    #define BAR_HEIGHT @"HEIGHT"
    #define COLOR @"COLOR"
    #define CATEGORY @"CATEGORY"

    #define AXIS_START 0
    #define AXIS_END 50

    @synthesize data;
    @synthesize hostingView = _hostingView;
    @synthesize graph = _graph;


    // Initialise the bar plot in the provided hosting
    -(id)initWithHostingView:(CPTGraphHostingView *)hostingView
    {
        self = [super init];
    
    if ( self != nil ) {
        self.hostingView = hostingView;
        self.graph = nil;
    }
    
    
    NSLog(@"Bar Plot: I'm in the initWithHostingView (in the barplot.m file)");
    
    return self;
    }


    - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
    {
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        
        self.data = [NSMutableArray array];
        
        int bar_heights[] = {20,30};
        
        
        UIColor *colors[] = {
            [UIColor redColor],
            [UIColor blueColor],
            [UIColor orangeColor],
            [UIColor purpleColor]};
        
        
        NSString *categories[] = {@"", @""};
        
        
        
        for (int i = 0; i < 2 ; i++){
            double position = i*20; //Bars will be 10 pts away from each other
            double height = bar_heights[i];
            
            NSDictionary *bar = [NSDictionary dictionaryWithObjectsAndKeys:
                                 [NSNumber numberWithDouble:position],BAR_POSITION,
                                 [NSNumber numberWithDouble:height],BAR_HEIGHT,
                                 colors[i],COLOR,
                                 categories[i],CATEGORY,
                                 nil];
            [self.data addObject:bar];
            
        }
        [self generateBarPlot];
    }
    return self;
    }


    - (void)generateBarPlot
    {
    //Create host view
    /*self.hostingView = [[CPTGraphHostingView alloc] 
                        initWithFrame:[[UIScreen mainScreen]bounds]];
    [self.view addSubview:self.hostingView];
    
    
    
    //Create graph and set it as host view's graph
    self.graph = [[CPTXYGraph alloc] initWithFrame:self.hostingView.bounds];
    [self.hostingView setHostedGraph:self.graph];*/
    
    
    
    // Create a graph object which we will use to host just one scatter plot.
    CGRect frame = [self.hostingView bounds];
    self.graph = [[CPTXYGraph alloc] initWithFrame:frame];
    
	// Tie the graph we've created with the hosting view.
    self.hostingView.hostedGraph = self.graph;
    
    
    
    //set graph padding and theme
    self.graph.plotAreaFrame.paddingTop = 20.0f;
    self.graph.plotAreaFrame.paddingRight = 20.0f;
    self.graph.plotAreaFrame.paddingBottom = 70.0f;
    self.graph.plotAreaFrame.paddingLeft = 70.0f;
    [self.graph applyTheme:[CPTTheme themeNamed:kCPTDarkGradientTheme]];
    
    
    
    // Gets rid of decimal on years
    NSNumberFormatter *labelFormatter = [[NSNumberFormatter alloc] init];
	labelFormatter.maximumFractionDigits = 0;
    
    
    
    //set axes ranges
    CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)self.graph.defaultPlotSpace;
    plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:
                        CPTDecimalFromFloat(AXIS_START)
                                                    length:CPTDecimalFromFloat((AXIS_END - AXIS_START))];
    plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:
                        CPTDecimalFromFloat(AXIS_START)
                                                    length:CPTDecimalFromFloat((AXIS_END - AXIS_START))];
    
    
    
    
    CPTXYAxisSet *axisSet = (CPTXYAxisSet *)self.graph.axisSet;
    //set axes' title, labels and their text styles
    CPTMutableTextStyle *textStyle = [CPTMutableTextStyle textStyle];
    textStyle.fontName = @"Helvetica";
    textStyle.fontSize = 14;
    textStyle.color = [CPTColor whiteColor];
    
    
    
    axisSet.xAxis.title = @"A";
    axisSet.yAxis.title = @"B";
    axisSet.xAxis.titleTextStyle = textStyle;
    axisSet.yAxis.titleTextStyle = textStyle;
    axisSet.xAxis.titleOffset = 30.0f;
    axisSet.yAxis.titleOffset = 40.0f;
    axisSet.xAxis.labelTextStyle = textStyle;
    axisSet.yAxis.labelTextStyle = textStyle;
    axisSet.xAxis.labelOffset = 3.0f;
    axisSet.yAxis.labelOffset = 3.0f;
    
    
    
    //set axes' line styles and interval ticks
    CPTMutableLineStyle *lineStyle = [CPTMutableLineStyle lineStyle];
    lineStyle.lineColor = [CPTColor whiteColor];
    lineStyle.lineWidth = 3.0f;
    axisSet.xAxis.axisLineStyle = lineStyle;
    axisSet.yAxis.axisLineStyle = lineStyle;
    axisSet.xAxis.majorTickLineStyle = lineStyle;
    axisSet.yAxis.majorTickLineStyle = lineStyle;
    axisSet.xAxis.majorIntervalLength = CPTDecimalFromFloat(5.0f);
    axisSet.yAxis.majorIntervalLength = CPTDecimalFromFloat(5.0f);
    axisSet.xAxis.majorTickLength = 10.0f;
    axisSet.yAxis.majorTickLength = 10.0f;
    axisSet.xAxis.minorTickLineStyle = lineStyle;
    axisSet.yAxis.minorTickLineStyle = lineStyle;
    axisSet.xAxis.minorTicksPerInterval = 1;
    axisSet.yAxis.minorTicksPerInterval = 1;
    axisSet.xAxis.minorTickLength = .0f;
    axisSet.yAxis.minorTickLength = .0f;
    axisSet.xAxis.labelFormatter = labelFormatter;
    axisSet.yAxis.labelFormatter = labelFormatter;
    
    
    
    // Create bar plot and add it to the graph
    CPTBarPlot *plot = [[CPTBarPlot alloc] init] ;
    plot.delegate = self;
    plot.dataSource = self;
    plot.barWidth = [[NSDecimalNumber decimalNumberWithString:@"5.0"]
                     decimalValue];
    plot.barOffset = [[NSDecimalNumber decimalNumberWithString:@"10.0"]
                      decimalValue];
    plot.barCornerRadius = 5.0;
    
    
    
    // Remove bar outlines
    CPTMutableLineStyle *borderLineStyle = [CPTMutableLineStyle lineStyle];
    borderLineStyle.lineColor = [CPTColor clearColor];
    plot.lineStyle = borderLineStyle;
    
    
    
    // Identifiers are handy if you want multiple plots in one graph
    plot.identifier = @"chocoplot";
    [self.graph addPlot:plot];
    }



    -(NSUInteger)numberOfRecordsForPlot:(CPTPlot *)plot
    {
    if ( [plot.identifier isEqual:@"chocoplot"] ) 
    {
        return [self.data count];
    }
    
    return 0;
    }



    -(NSNumber *)numberForPlot:(CPTPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index
    {
    if ( [plot.identifier isEqual:@"chocoplot"] )
    {
        
        NSDictionary *bar = [self.data objectAtIndex:index];
        
        
        if( fieldEnum == 2 ) {
            return [bar valueForKey:BAR_POSITION];
            //return [NSNumber numberWithDouble:20];
        }
        else if( fieldEnum == 3 ) {
            return [bar valueForKey:BAR_HEIGHT];
            //return [NSNumber numberWithDouble:20];
        }
        
    }
    NSLog(@"numberForPlot return before");
    return [NSNumber numberWithDouble:15];
    }

    @end