step counter sensor in androi d code example

Example: step counter sensor in android

public class SensorFilter {
 
  private SensorFilter() {
  }
 
  public static float sum(float[] array) {
    float retval = 0;
    for (int i = 0; i < array.length; i++) {
      retval += array[i];
    }
    return retval;
  }
 
  public static float[] cross(float[] arrayA, float[] arrayB) {
    float[] retArray = new float[3];
    retArray[0] = arrayA[1] * arrayB[2] - arrayA[2] * arrayB[1];
    retArray[1] = arrayA[2] * arrayB[0] - arrayA[0] * arrayB[2];
    retArray[2] = arrayA[0] * arrayB[1] - arrayA[1] * arrayB[0];
    return retArray;
  }
 
  public static float norm(float[] array) {
    float retval = 0;
    for (int i = 0; i < array.length; i++) {
      retval += array[i] * array[i];
    }
    return (float) Math.sqrt(retval);
  }
 
 
  public static float dot(float[] a, float[] b) {
    float retval = a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
    return retval;
  }
 
  public static float[] normalize(float[] a) {
    float[] retval = new float[a.length];
    float norm = norm(a);
    for (int i = 0; i < a.length; i++) {
      retval[i] = a[i] / norm;
    }
    return retval;
  }
 
}