iOS calculate g-force - ios

Question

Its simple, I need to make a label in my project that says the current g-force from the accelerometer. I have found some code but I don't know where to put it in my code. I am guessing that I need to put it into a void statement but I am not sure. Please point me in the right direction.
sx = acceleration.x * kFilteringFactor + sx * (1.0 - kFilteringFactor);
sy = acceleration.y * kFilteringFactor + sy * (1.0 - kFilteringFactor);
sz = acceleration.z * kFilteringFactor + sz * (1.0 - kFilteringFactor);
float aValue = sqrt(sx*sx+sy*sy+sz*sz);
[gforcelabel setText:[NSString stringWithFormat:#"%.2f",aValue]];

Answer 1

I wouldn't bother with UIAccelerometerDelegate anymore considering it's unlikely at this point you'll need to maintain compatibility for anything below iOS 5. As linked in the other answer, you'll want to use Core Motion instead, specifically, CMMotionManager, which is available in iOS 5 and up. It's easy enough to use too, all you have to do is create an instance of the motion manager (you can only have one), set it's update interval (optional), and start monitoring the specified motion events.
if (!self.manager) {
self.manager = [CMMotionManager new];
}
if (self.manager.isAccelerometerActive) {
[self.manager stopAccelerometerUpdates];
}
NSOperationQueue *queue = [NSOperationQueue new];
[self.manager setAccelerometerUpdateInterval:1.0 / 30.0]; // 30 Updates Per Second
[self.manager startAccelerometerUpdatesToQueue:queue withHandler:^(CMAccelerometerData *accelerometerData, NSError *error) {
NSLog(#"X: %f Y: %f Z: %f",accelerometerData.acceleration.x,accelerometerData.acceleration.y,accelerometerData.acceleration.z);
}];
The code I've provided creates a new operation queue on which to process the accelerometer updates, and if you want to update the UI from within the block, you'll have to move back to the main thread first. If you aren't doing any heavy processing within the block, and just need to update the UI (as it looks like you do), you can simply pass [NSOperationQueue mainQueue], instead of creating a new queue.
It's also worth noting that the motion manager can do more than just monitor acceleration data, it also has update blocks for the magnetometer, gyroscope, and device motion. Info can be found in the documentation

Answer 2

UIAccelerometer was deprecated in iOS 5.0. You should use the Core Motion Library instead.
If we suppose that you are targeting iOS 5.0, the code you've listed above would live in a view controller that implements the UIAccelerometerDelegate Protocol. To be specific, you would define the following protocol method and move your code inside the body of this method:
- (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration

Answer 3

I figured out exactly how to do it...
Viewcontroller.h
IBOutlet UILabel *currentg;
IBOutlet UILabel *avgAccelLabel;
float avgAccel;
float currentAccel;
int accelCount;
float accelX;
float accelY;
float accelZ;
UIAccelerometer *accelerometer;
Viewcontroller.m
//Use a basic low-pass filter to only keep the gravity in the accelerometer values
accelX = acceleration.x; //* kFilteringFactor + accelX * (1.0 - kFilteringFactor);
accelY = acceleration.y; //* kFilteringFactor + accelY * (1.0 - kFilteringFactor);
accelZ = acceleration.z; //* kFilteringFactor + accelZ * (1.0 - kFilteringFactor);
//calculate acceleration resultant
float accel = sqrt((ABS(accelX)*ABS(accelX))+(ABS(accelY)*ABS(accelY))+ (ABS(accelZ)*ABS(accelZ)));
//keep track of average accel
avgAccel = ((avgAccel * accelCount) + accel)/(accelCount + 1);
currentAccel = (accel);
accelCount++;
//display avg accel
NSString *avgAccelString = [NSString stringWithFormat:#"%.2f%#", avgAccel, #""];
avgAccelLabel.text = avgAccelString;
NSString *currentAccellString = [NSString stringWithFormat:#"%.2f%#",currentAccel, #"" ];
currentg.text = currentAccellString;
viewdidload
self.accelerometer = [UIAccelerometer sharedAccelerometer];
self.accelerometer.updateInterval = 0.4;
self.accelerometer.delegate = self;