Frog not moving

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerMovement : MonoBehaviour {

    private Animator playerAnimator;
    private float moveHorizontal;
    private float moveVertical;
    private Vector3 movement;


    // Use this for initialization
    void Start () {

        playerAnimator = GetComponent<Animator> ();

    }

    // Update is called once per frame
    void Update () {
        moveHorizontal = Input.GetAxisRaw ("Horizontal");
        moveVertical = Input.GetAxisRaw ("Vertical");

        movement = new Vector3 (moveHorizontal, 0.0f, moveVertical);
    }

    void FixedUpdate() {
        if (movement != Vector3.zero) {

            playerAnimator.SetFloat("Speed", 3f);
        }   else {  playerAnimator.SetFloat("Speed", 0f);
        }

    }



 }