SensorFilter = function(size) {
  /**
   * Last index used.
   * @type {number}
   * @private
   */
  this.lastIndex_ = -1;

  /**
   * Number of history entries.
   * @type {number}
   * @private
   */
  this.size_ = size;

  /**
   * A list of all history entries, each one 3 elements of XYZ.
   * @type {!Float32Array}
   * @private
   */
  this.elements_ = new Float32Array(size * 3);

  /**
   * Scratch vec3 for temp math.
   * @type {!Float32Array}
   * @private
   */
  this.tempVec3_ = new Float32Array(3);
}
Sensor value filter.
@param {number} size History size.
@constructor