.h:
//
//  CPTTestAppBarChartController.h
//  CPTTestApp-iPhone
//

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

@interface CPTTestAppBarChartController : UIViewController <CPTPlotDataSource>
{
@private
	CPTXYGraph *barChart;
	NSTimer *timer;
}

@property(readwrite, retain, nonatomic) NSTimer *timer;

-(void)timerFired;

@end


.m:

//
//  CPTTestAppBarChartController.m
//  CPTTestApp-iPhone
//

#import "CPTTestAppBarChartController.h"

@implementation CPTTestAppBarChartController

@synthesize timer;

-(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation
{
	return YES;
}

#pragma mark -
#pragma mark Initialization and teardown
-(void) viewDidLoad{
	NSLog(@"Hello World!");
	[super viewDidLoad];
}
-(void)viewDidAppear:(BOOL)animated
{
	[self timerFired];
#ifdef MEMORY_TEST
	self.timer = [NSTimer scheduledTimerWithTimeInterval:0.1 target:self
												selector:@selector(timerFired) userInfo:nil repeats:YES];
#endif
}

-(void)timerFired
{
#ifdef MEMORY_TEST
	static NSUInteger counter = 0;

	NSLog(@"\n----------------------------\ntimerFired: %lu", counter++);
#endif

	[barChart release];

    // Create barChart from theme
    barChart = [[CPTXYGraph alloc] initWithFrame:CGRectZero];
	CPTTheme *theme = [CPTTheme themeNamed:kCPTDarkGradientTheme];
    [barChart applyTheme:theme];
	CPTGraphHostingView *hostingView = (CPTGraphHostingView *)self.view;
    hostingView.hostedGraph = barChart;

    // Border
    barChart.plotAreaFrame.borderLineStyle = nil;
    barChart.plotAreaFrame.cornerRadius = 0.0f;

    // Paddings
    barChart.paddingLeft = 0.0f;
    barChart.paddingRight = 0.0f;
    barChart.paddingTop = 0.0f;
    barChart.paddingBottom = 0.0f;

    barChart.plotAreaFrame.paddingLeft = 70.0;
	barChart.plotAreaFrame.paddingTop = 20.0;
	barChart.plotAreaFrame.paddingRight = 20.0;
	barChart.plotAreaFrame.paddingBottom = 80.0;

    // Graph title
    barChart.title = @"Graph Title\nLine 2";
    CPTMutableTextStyle *textStyle = [CPTTextStyle textStyle];
    textStyle.color = [CPTColor grayColor];
    textStyle.fontSize = 16.0f;
	textStyle.textAlignment = CPTTextAlignmentCenter;
    barChart.titleTextStyle = textStyle;
    barChart.titleDisplacement = CGPointMake(0.0f, -20.0f);
    barChart.titlePlotAreaFrameAnchor = CPTRectAnchorTop;

	// Add plot space for horizontal bar charts
    CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)barChart.defaultPlotSpace;
    plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0.0f) length:CPTDecimalFromFloat(300.0f)];
    plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromFloat(0.0f) length:CPTDecimalFromFloat(16.0f)];


	CPTXYAxisSet *axisSet = (CPTXYAxisSet *)barChart.axisSet;
    CPTXYAxis *x = axisSet.xAxis;
    x.axisLineStyle = nil;
    x.majorTickLineStyle = nil;
    x.minorTickLineStyle = nil;
    x.majorIntervalLength = CPTDecimalFromString(@"5");
    x.orthogonalCoordinateDecimal = CPTDecimalFromString(@"0");
	x.title = @"X Axis";
    x.titleLocation = CPTDecimalFromFloat(7.5f);
	x.titleOffset = 55.0f;

	// Define some custom labels for the data elements
	x.labelRotation = M_PI/4;
	x.labelingPolicy = CPTAxisLabelingPolicyNone;
	NSArray *customTickLocations = [NSArray arrayWithObjects:[NSDecimalNumber numberWithInt:1], [NSDecimalNumber numberWithInt:5], [NSDecimalNumber numberWithInt:10], [NSDecimalNumber numberWithInt:15], nil];

	NSArray *xAxisLabels = [NSArray arrayWithObjects:@"Label A", @"Label B", @"Label C", @"Label D", @"Label E", nil];
	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 + x.majorTickLength;
		newLabel.rotation = M_PI/4;
		[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 = @"Y Axis";
	y.titleOffset = 45.0f;
    y.titleLocation = CPTDecimalFromFloat(150.0f);

    // First bar plot
    CPTBarPlot *barPlot = [CPTBarPlot tubularBarPlotWithColor:[CPTColor darkGrayColor] horizontalBars:NO];
    barPlot.baseValue = CPTDecimalFromString(@"0");
    barPlot.dataSource = self;
    barPlot.barOffset = CPTDecimalFromFloat(-0.25f);
    barPlot.identifier = @"Bar Plot 1";
    [barChart addPlot:barPlot toPlotSpace:plotSpace];

    // Second bar plot
    barPlot = [CPTBarPlot tubularBarPlotWithColor:[CPTColor blueColor] horizontalBars:NO];
    barPlot.dataSource = self;
    barPlot.baseValue = CPTDecimalFromString(@"0");
    barPlot.barOffset = CPTDecimalFromFloat(0.25f);
    barPlot.barCornerRadius = 2.0f;
    barPlot.identifier = @"Bar Plot 2";
    [barChart addPlot:barPlot toPlotSpace:plotSpace];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning]; // Releases the view if it doesn't have a superview
    // Release anything that's not essential, such as cached data
}

#pragma mark -
#pragma mark Plot Data Source Methods

-(NSUInteger)numberOfRecordsForPlot:(CPTPlot *)plot {
    return 16;
}

-(NSNumber *)numberForPlot:(CPTPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index
{
    NSDecimalNumber *num = nil;
    if ( [plot isKindOfClass:[CPTBarPlot class]] ) {
		switch ( fieldEnum ) {
			case CPTBarPlotFieldBarLocation:
				num = (NSDecimalNumber *)[NSDecimalNumber numberWithUnsignedInteger:index];
				break;
			case CPTBarPlotFieldBarTip:
				num = (NSDecimalNumber *)[NSDecimalNumber numberWithUnsignedInteger:(index+1)*(index+1)];
				if ( [plot.identifier isEqual:@"Bar Plot 2"] )
					num = [num decimalNumberBySubtracting:[NSDecimalNumber decimalNumberWithString:@"10"]];
				break;
		}
    }

    return num;
}

-(CPTFill *) barFillForBarPlot:(CPTBarPlot *)barPlot recordIndex:(NSNumber *)index;
{
	return nil;
}

@end