从加速度计获得速度

Question

大家好我有一个JavaScript功能来加速。我想通过加速来获得速度。

有人可以帮帮我吗？没有方法可以在API中获得 speed 。

function getDataFromSensor() {
  //call js.call to get data FROM accelerometer  
  var rtrn = js.call('api.sensors.getAccelerometer()', {});
  // parse JSONObject
  var obj = JSON.parse(rtrn);
  //get value of axe x
  var x = obj.accelerometerX;
  //get value of axe y 
  var y = obj.accelerometerY;
  //get value of axe z
  var z = obj.accelerometerZ;
  // use gravity according to your place in this example I Choose 9 
  var result = (x * x + y * y + z * z) / (9 * 9);
  //If mobile move any direction then the following condition will become true 
  if (result > 2) {
    //Generate random number between 0 and 1 every time and display on text view

    js.setProperty('menu.Text_1', 'text', "err");
  } else {
    js.setProperty('menu.Text_1', 'text', "result:" + result);
  }

}