Make joystick rotate object

Hi i just had a problem trying to make a 2d top down shooter. How can i get the joystick position to change the rotation of the graphic as its turned(moving is done). This is the joysticks code:

using UnityEngine; using UnityEngine.UI; using UnityEngine.EventSystems; using System.Collections;

public class JoystickController : MonoBehaviour, IDragHandler, IPointerUpHandler, IPointerDownHandler { private Image backgroundImg; private Image JoystickImg;

 public Vector3 InputDirection{ set; get; }
 public float angle;

 public GameObject Graphic;

 private Vector3 rotationDirection;
 private Quaternion rotation;



 private void Start(){
     backgroundImg = GetComponent<Image> ();
     JoystickImg = transform.GetChild(0).GetComponent<Image> ();
 }

 public virtual void OnDrag(PointerEventData ped){

     Vector2 pos = Vector2.zero;
     if (RectTransformUtility.ScreenPointToLocalPointInRectangle (backgroundImg.rectTransform, ped.position, ped.pressEventCamera, out pos)) {
         pos.x = (pos.x / backgroundImg.rectTransform.sizeDelta.x);
         pos.y = (pos.y / backgroundImg.rectTransform.sizeDelta.y);

         float x = (backgroundImg.rectTransform.pivot.x == 1) ? pos.x * 2 + 1 : pos.x * 2 - 1;
         float y = (backgroundImg.rectTransform.pivot.y == 1) ? pos.y * 2 + 1 : pos.y * 2 - 1;

         InputDirection = new Vector3 (x, 0, y);

         InputDirection = (InputDirection.magnitude > 1) ? InputDirection.normalized : InputDirection;

         JoystickImg.rectTransform.anchoredPosition = new Vector3 (InputDirection.x * (backgroundImg.rectTransform.sizeDelta.x / 3), InputDirection.z * (backgroundImg.rectTransform.sizeDelta.y / 3));

     }
 }

 public virtual void OnPointerDown(PointerEventData ped){

     OnDrag (ped);
 }

 public virtual void OnPointerUp(PointerEventData ped){

     InputDirection = Vector3.zero;
     JoystickImg.rectTransform.anchoredPosition = Vector3.zero;
 }

 void Update(){
 }

}

Thank you!