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2014/10/15 ¤U¤È 10:14:12
iphone Programming Glossary: signalsDetecting noise via mic while playing a song on iPhone http://stackoverflow.com/questions/11993844/detecting-noise-via-mic-while-playing-a-song-on-iphone fft noise share improve this question You just want to know how much noise is in the environment and you have two signals the original one and the recorded one Then your solution is perfectly fine. You need to synchronize the signals and find.. two signals the original one and the recorded one Then your solution is perfectly fine. You need to synchronize the signals and find some number which gives you similarity. You can even avoid fft and use the original signal in a proper presentation.. avoid fft and use the original signal in a proper presentation . Autocorellation is a nice way to synchronice your signals. Autocorellation index is a number which gives you the similarity. Of course if the volume is lower the noise is relative..
CGAffineTransformInvert: singular matrix in UIImagePickerController with showsCameraControls = NO http://stackoverflow.com/questions/13708496/cgaffinetransforminvert-singular-matrix-in-uiimagepickercontroller-with-showsca the console Error CGAffineTransformInvert singular matrix. When I run the app every time I rotate or move about which signals a rotate the device while the camera is up something happens here . I tried it on both my iPhone 4 and iPad Mini with the..
How do you use a moving average to filter out accelerometer values in iPhone OS http://stackoverflow.com/questions/2272527/how-do-you-use-a-moving-average-to-filter-out-accelerometer-values-in-iphone-os is quick and easy to implement e.g. xf k xf 1.0 k x yf k yf 1.0 k y where x y are the raw unfiltered X Y accelerometer signals xf yf are the filtered output signals and k determines the time constant of the filters typically a value between 0.9 and.. k xf 1.0 k x yf k yf 1.0 k y where x y are the raw unfiltered X Y accelerometer signals xf yf are the filtered output signals and k determines the time constant of the filters typically a value between 0.9 and 0.9999... where a bigger k means a longer.. on the LHS of the expression above. Note also that we are assuming here that you will be sampling the accelerometer signals at regular time intervals e.g. every 10 ms. The time constant will be a function both of k and of this sampling interval...
Applying Effect to iPhone Camera Preview “Video” http://stackoverflow.com/questions/4893620/applying-effect-to-iphone-camera-preview-video the dispatch queue but I am not sure how much it is actually helping. Basically every 8 10 frames a flag is set that signals captureOutput didOutputSampleBuffer fromConnection to return right away rather than process the frame. The flag is reset..
programatically measuring carrier's signal strength in iPhone device http://stackoverflow.com/questions/4954389/programatically-measuring-carriers-signal-strength-in-iphone-device us app baralarm id364878555 mt 8 Any help is appreciated because its very urgent. iphone objective c cocoa touch signals share improve this question I briefly looked at the VAFieldTest project located at Github . There seems to be getSignalStrength..
http://stackoverflow.com/questions/5214197/simple-iphone-motion-detect narrow signal processing on CMDeviceMotion.userAcceleration. This is because every rotation results in accelerometer signals as well. Create a CMDeviceMotionHandler as described in startDeviceMotionUpdatesToQueue withHandler Your CMDeviceMotionHandler..
What is the range of bluetooth and is it strictly 1:1? http://stackoverflow.com/questions/658899/what-is-the-range-of-bluetooth-and-is-it-strictly-11 design is sub optimal. I don't know how good the iPhone is in this respect. Walls Generally walls attenuate Bluetooth signals. However sometimes they are useful reflectors. Quality of hardware Some chips work better than others. Even different firmware..
Need to find Distance using Gyro+Accelerometer http://stackoverflow.com/questions/6647314/need-to-find-distance-using-gyroaccelerometer for displacements in y and z and basic geometry is the Pythagorean theorem So once you have your accelerometer signals passed through a low pass filter and binned in time with sampling interval dt you can find the displacement in x as pardon..
Exception Types in iOS crash logs http://stackoverflow.com/questions/7446655/exception-types-in-ios-crash-logs is a segmentation fault meaning you are trying to access an invalid memory address. Those exceptions in fact they are signals are not related to Objective C but C. So you can get such an exception without Objective C objects. Note that a signal is.. with @try and @catch blocks. You may set a signal handler with the signal and sigaction functions. Keep in mind some signals like SIGABRT cannot be blocked. You can check the Wikipedia page about signals if you want more informations. That said.. sigaction functions. Keep in mind some signals like SIGABRT cannot be blocked. You can check the Wikipedia page about signals if you want more informations. That said to resume SIGSEGV Segmentation fault Access to an invalid memory address. The address..
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