how to detect direction of shake in iphone

I have an image of a bottle, whenever us开发者_Go百科er shakes the device i want to move that image in that direction. like up, down, left or right.

For example: if user is shaking the device in left direction i want to move that image in left direction.

i can detect shake event using

- (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event {
if(event.subtype==UIEventSubtypeMotionShake)
{/*some code*/} }

but i dont know how to detect the direction.

i dont even if this is possible or not. please help me.

A shake is typically a back and forth movement. Use the accelerometer data to detect a sudden movement in one particular direction (e.g. left) or a tilt towards a different orientation.

You can get user motion values using CMMotionManager class.Please refer the following link

http://developer.apple.com/library/ios/#documentation/CoreMotion/Reference/CMMotionManager_Class/Reference/Reference.html#//apple_ref/occ/cl/CMMotionManager

Filter your acceleration and gyro dat detect direction of motion.