2014/10/15 下午 10:03:29

iphone Programming Glossary: acceleration

http://stackoverflow.com/questions/1994018/measuring-velocity-via-iphone-sdk

on my research it should be possible to do this but seems extremely complicated and error prone. Translating from acceleration to velocity can be tricky to begin with plus the iPhone accelerometer data can be noisy . I'm familiar with the SDK example..

Getting displacement from accelerometer data with Core Motion

http://stackoverflow.com/questions/4449565/getting-displacement-from-accelerometer-data-with-core-motion

rotMat This works really well. More problems arise anyway when I try to find the displacement in space during an acceleration. The Apple Teapot example with Core Motion just adds the x y and z values of the acceleration vector to the position vector... in space during an acceleration. The Apple Teapot example with Core Motion just adds the x y and z values of the acceleration vector to the position vector. This apart from having not much sense has the result of returning the object to the original.. vector. This apart from having not much sense has the result of returning the object to the original position after an acceleration. Since the acceleration goes from positive to negative or vice versa . They did it like this translation.x userAcceleration.x..

how can I use animation in cocos2d?

http://stackoverflow.com/questions/486609/how-can-i-use-animation-in-cocos2d

quarter circle. Likewise if you used 0.999f pi the circle would rotate in a clockwise manner. You'll want to implement acceleration and deceleration of your wheel and for those a CAKeyframeAnimation would take the place of the CABasicAnimation in this..

How to create custom easing function with Core Animation?

http://stackoverflow.com/questions/5161465/how-to-create-custom-easing-function-with-core-animation

here. iphone cocoa touch core animation tween share improve this question I found this Cocoa with Love Parametric acceleration curves in Core Animation But I think it can be made a little simpler and more readable by using blocks. So we can define..

Tap pressure strength detection using accelerometer

http://stackoverflow.com/questions/5179426/tap-pressure-strength-detection-using-accelerometer

page . I'm wondering how that's supposed to work if the iPad lays flat on the table. No movement no measurable acceleration no iphone ipad uikit accelerometer tap share improve this question Some good answers. Here's some working code. I implemented.. #pragma UIAccelerometerDelegate methods void accelerometer UIAccelerometer accelerometer didAccelerate UIAcceleration acceleration int sz sizeof pressureValues sizeof pressureValues 0 set current pressure value pressureValues currentPressureValueIndex.. sizeof pressureValues sizeof pressureValues 0 set current pressure value pressureValues currentPressureValueIndex sz acceleration.z if setNextPressureValue 0 calculate average pressure float total 0.0f for int loop 0 loop sz loop total pressureValues..

Simple iPhone motion detect

http://stackoverflow.com/questions/5214197/simple-iphone-motion-detect

as described in startDeviceMotionUpdatesToQueue withHandler Your CMDeviceMotionHandler should do something like float accelerationThreshold 0.2 or whatever is appropriate play around with different values CMAcceleration userAcceleration deviceMotion.userAcceleration.. around with different values CMAcceleration userAcceleration deviceMotion.userAcceleration if fabs userAcceleration.x accelerationThreshold fabs userAcceleration.y accelerationThreshold fabs userAcceleration.z accelerationThreshold enter code here Basically.. deviceMotion.userAcceleration if fabs userAcceleration.x accelerationThreshold fabs userAcceleration.y accelerationThreshold fabs userAcceleration.z accelerationThreshold enter code here Basically that's it. Bear in mind that every acceleration..

track small movements of iphone with no GPS

http://stackoverflow.com/questions/6158176/track-small-movements-of-iphone-with-no-gps

already Thanks a lot iphone ios4 gps accelerometer gyroscope share improve this question If you integrate the acceleration twice you get position but the error is horrible. It is useless in practice. Here is an explanation why Google Tech Talk..

Store orientation to an array - and compare

http://stackoverflow.com/questions/6368618/store-orientation-to-an-array-and-compare

And as for tc's question does the orientation relative to North matter I guess not. It is far easier to compare the acceleration vectors than orientations Euler angles rotation matrices quaternions as tc pointed that out. If you are using acceleration.. vectors than orientations Euler angles rotation matrices quaternions as tc pointed that out. If you are using acceleration data you have 3 dimensional vectors at each time point the x y z coordinates. I would simply compute Dist i j SQRT A i X..

Distance moved by Accelerometer

http://stackoverflow.com/questions/6645126/distance-moved-by-accelerometer

iphone xcode accelerometer distance share improve this question You get position by integrating the linear acceleration twice but the error is horrible. It is useless in practice. Here is an explanation why Google Tech Talk at 23 20. I highly..

Need to find Distance using Gyro+Accelerometer

http://stackoverflow.com/questions/6647314/need-to-find-distance-using-gyroaccelerometer

interval dt you can find the displacement in x as pardon my C... float dx 0.0f float vx 0.0f for int i 1 i n i vx acceleration_x i 1 acceleration_x i 2.0f dt dx vx dt and similarly for dy and dz. Here float acceleration_x n contains x acceleration.. can find the displacement in x as pardon my C... float dx 0.0f float vx 0.0f for int i 1 i n i vx acceleration_x i 1 acceleration_x i 2.0f dt dx vx dt and similarly for dy and dz. Here float acceleration_x n contains x acceleration values from start.. 0.0f for int i 1 i n i vx acceleration_x i 1 acceleration_x i 2.0f dt dx vx dt and similarly for dy and dz. Here float acceleration_x n contains x acceleration values from start to end of measurement at times 0 dt 2 dt 3 dt ... n 1 dt. To find the total..

Lock Unlock events iphone

http://stackoverflow.com/questions/706344/lock-unlock-events-iphone

2 seconds for wiggle Deprecated in iOS5 void accelerometer UIAccelerometer accelerometer didAccelerate UIAcceleration acceleration NSLog @ STATUS Update from accelerometer _notActiveTimer invalidate _notActiveTimer NSTimer scheduledTimerWithTimeInterval..