Question

我正在尝试为 TotalAccelerate 制作简单的移动平均线。简单地说，移动平均线应该采用 TotalAccelerate 向量的4个样本并在运行时对它们求平均值。然后移动一个样本并平均接下来的四个样本，依此类推。我写的代码不起作用。它崩溃的原因我不知道。我应该使用单独的线程来进行计算吗？如果你写一个伪代码，我将不胜感激。

double TotalAccelerate;
ArrayList<Double> listPeaks;
//for Accelermeter
sm = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
sensorText = (TextView) findViewById(R.id.sensor);
accelermeter = sm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
sm.registerListener(this, accelermeter, SensorManager.SENSOR_DELAY_NORMAL);
mDetector = new GestureDetectorCompat(this, new MyGestureListener());

  @Override
public final void onSensorChanged(SensorEvent event) {
    // The light sensor returns a single value.
    // Many sensors return 3 values, one for each axis.

      //If my ToggleButton Ischecked and isListening=true.(at Oncreate method)
    if (isListening) {
        double xx = event.values[0];
        double yy = event.values[1];
        double zz = event.values[2];
         //The result will be one vector of array
        TotalAccelerate = Math.round(Math.sqrt(Math.pow(xx, 2)
                + Math.pow(yy, 2)
                + Math.pow(zz, 2)));
        Log.i(DEBUG, "Accelerometer = " + TotalAccelerate);

        listPeaks.add(TotalAccelerate);
        //findPeaks(listPeaks);

        Log.i(DEBUG, "list values " + listPeaks);
        //Find moving average - window size= 4
        MovingAverage ma = new MovingAverage(4);
        ma.newNum(TotalAccelerate);
        float valueAfterMovingAverage = (float) ma.getAvg();
        sensorText.setText((int) valueAfterMovingAverage);
    }

}

public Queue<Double> window = new LinkedList<Double>();
public int p;
public double sum;

///Moving Average class.
public class MovingAverage {
    public MovingAverage(int period) {
        assert period > 0 : "Period must be a positive integer";
        p = period;
    }

    public void newNum(double num) {
        sum += num;
        window.add(num);
        if (window.size() > p) {
            sum -= window.remove();
        }
    }

    public double getAvg() {
        if (window.isEmpty()) return 0; // technically the average is undefined
        return sum / window.size();
    }

}

这是我得到的错误：

at android.content.res.Resources.getText(Resources.java:275)
                                                                          at android.widget.TextView.setText(TextView.java:4264)
                                                                          at com.example.arduinosensors.MainActivity.onSensorChanged(MainActivity.java:230)
                                                                          at android.hardware.SystemSensorManager$SensorEventQueue.dispatchSensorEvent(SystemSensorManager.java:436)
                                                                          at android.os.MessageQueue.nativePollOnce(Native Method)
                                                                          at android.os.MessageQueue.next(MessageQueue.java:143)
                                                                          at android.os.Looper.loop(Looper.java:122)
                                                                          at android.app.ActivityThread.main(ActivityThread.java:5354)
                                                                          at java.lang.reflect.Method.invoke(Native Method)
                                                                          at java.lang.reflect.Method.invoke(Method.java:372)
                                                                          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908)
                                                                          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703)

Answer 1

更改此行：

sensorText.setText((int) valueAfterMovingAverage);

为：

sensorText.setText(String.valueOf((int) valueAfterMovingAverage));

加速度传感器的移动平均法

1 个答案: