A clickable minimap that places a pointer sprite at the position where you clicked and returns a Vector2 with a range of -1 to 1 in both dimensions

Unity3D_MinimapComponent.cs

using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;
using Wirelab.Pages;

public class MinimapComponent : BaseComponent, IPointerClickHandler {

    public GameObject pointerPrefab;
    public DataEvent<Vector2> onClick;

    RectTransform rectTransform;
    Image mapImage;
    RectTransform pointer;
    Vector2 pointerOffset;

    Vector3 localPoint;
    Vector2 localNormal;

    void Awake () {
        rectTransform = (rectTransform != null) ? rectTransform : gameObject.GetComponent<RectTransform> ();
        mapImage = mapImage ?? gameObject.GetComponent<Image> ();
        Debug.Assert (pointerPrefab != null, "Missing pointerPrefab");
    }

    public void OnPointerClick (PointerEventData eventData) {
        if (pointer == null) {
            var go = GameObject.Instantiate (pointerPrefab, Vector3.zero, Quaternion.identity, transform);
            pointer = go.GetComponent<RectTransform> ();

            var image = go.GetComponentInChildren<Image> ();
            var sprite = image.sprite;
            if (sprite != null) {
                // use sprite pivot offset for placement
                var px = sprite.rect.width / 2 - sprite.pivot.x;
                var py = sprite.rect.height / 2 - sprite.pivot.y;
                if (image != null) pointerOffset = new Vector2 (px / 2, py / 2);
            }
        }

        pointer.gameObject.SetActive (true);

        localPoint = transform.InverseTransformPoint (eventData.pressPosition);
        PlacePointer (localPoint);

        localNormal.Set ((localPoint.x / rectTransform.rect.width + 0.5f) * 2 - 1, (localPoint.y / rectTransform.rect.height + 0.5f) * 2 - 1);

        DispatchDataEvent<Vector2> (onClick, localNormal);
    }

    public void Clear () {
        if (pointer != null) pointer.gameObject.SetActive (false);
    }

    // ---- private methods ----

    void PlacePointer (Vector2 position) {
        pointer.localPosition = position + pointerOffset;
        pointer.localScale = Vector3.one;
    }

}