can't stop getting signal sigbart trying to use a picker
===

I keeo on getting this error:

2012-07-19 22:46:23.214 Arrow Physics[14795:fe03] -[UIViewController numberOfComponentsInPickerView:]: unrecognized selector sent to instance 0x6848b10
2012-07-19 22:46:23.216 Arrow Physics[14795:fe03] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIViewController numberOfComponentsInPickerView:]: unrecognized selector sent to instance 0x6848b10'
*** First throw call stack:
(0x13c9022 0x155acd6 0x13cacbd 0x132fed0 0x132fcb2 0xc01d 0xcb2c 0x51d42 0x13cae42 0x1d81679 0x1d8b579 0x1d104f7 0x1d123f6 0x1d11ad0 0x139d99e 0x1334640 0x13004c6 0x12ffd84 0x12ffc9b 0x12b27d8 0x12b288a 0x13626 0x1e0d 0x1d75 0x1)
terminate called throwing an exception(lldb) 
        
am i using the number of components in picker view incorrectly

    
        #import "ArrowViewController.h"

        @interface ArrowViewController ()



        @end

        @implementation ArrowViewController 

        @synthesize Title;
        @synthesize progressView;
        @synthesize ContinueButton;
        @synthesize Credit;
        @synthesize pickerData;
        @synthesize singlePicker;
        @synthesize choice;

        - (void)viewDidLoad
        {
            [super viewDidLoad];
	        // Do any additional setup after loading the view, typically from a nib.
    timer=[NSTimer scheduledTimerWithTimeInterval:0.1 target:self                 selector:@selector(moreProgress) userInfo:nil repeats:YES];
        NSArray *array=[[NSArray alloc] initWithObjects:@"Force",@"Mass", nil];
        self.pickerData=array;
        [super viewDidLoad];
    }

    - (void)viewDidUnload
    {
        [self setTitle:nil];
        [self setProgressView:nil];
        [self setContinueButton:nil];
        [self setCredit:nil];
        [super viewDidUnload];
        self.singlePicker=nil;
        self.pickerData=nil;
        // Release any retained subviews of the main view.
    }

    - (BOOL)shouldAutorotateToInterfaceOrientation:  (UIInterfaceOrientation)interfaceOrientation
    {
        return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
    }
    -(void) moreProgress{
        progressView.progress+=0.025;
        Title.alpha=progressView.progress;
        Credit.alpha=progressView.progress;
        if (progressView.progress==1) {
            ContinueButton.alpha=1;
            [timer invalidate];
        }
        else{
        
        }

               }
    -(IBAction)buttonPressed {
	    NSInteger row=[singlePicker selectedRowInComponent:0];
        NSString *selected=[pickerData objectAtIndex:row];
        NSString *choice =[[NSString alloc] initWithFormat:@"You selected %@!",selected];
    
    
    }
    #pragma mark -
    #pragma mark Picker Data Source Methods
    //                     I think the error is here
    //                                I
    //                                I
    //                                V
    -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)singlePicker {
        return 1;
    }

    -(NSInteger)pickerView:(UIPickerView *)singlePicker numberOfRowsInComponent:   (NSInteger)component{
        return [pickerData count];
    }

    #pragma mark Picker Delegate Methods
    -(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{
        return [pickerData objectAtIndex:row];
    }

    @end
     
