Computing Feasible RIS Positions
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This tutorial explains how to determine the feasible RIS positions based on the location of the transmitter and the RIS target point(s).

.. note::

   Before executing this step, you must first compute and visualize the transmitter-only coverage map.  
   Please follow the `Computing Transmitter-Only Coverage Map` tutorial beforehand.

There are two ways to define the RIS target points:

1. **Using the Target Points from Clustering:**

   .. note::

      To use this option, you must first run the clustering algorithm to compute target points.  
      Refer to the `Finding RIS Target Points via K-means Clustering` tutorial before proceeding.

   In the GUI, select the radio button **"Use the target point(s) found via clustering algorithm"**. This will use the previously computed RIS target points to determine feasible RIS positions.

2. **Manually Entering Target Point Coordinates:**

   - Go to the labelframe **"Manual trials"** on the left side of the GUI.
   - Enter the number of RIS target points in the field **"Number of target points"**
   - Select the checkbox **"Enter the target point(s) manually"**.
   - A new input area will appear between the labelframe **"Manual trials"** and the labelframe **"Optimization algorithm"**.
   - Enter the x, y, z coordinates for each target point manually.

Final Step: **Compute Feasible RIS Positions**

   - After selecting or entering the target points, press the button **"Compute feasible RIS positions"**.
   - This will compute all feasible RIS positions that have line-of-sight (LoS) to both the transmitter and all RIS target points.
   - After execution:

      - A **binary poor coverage map** is displayed.
      - Target points are shown as **green 'X' symbols**.
      - Feasible RIS positions are marked with **green star symbols**.

.. figure:: computing_feasible_RIS_positions_Fig1.png
   :align: center
   :figwidth: 80%
   :name: computing_feasible_RIS_positions_Fig1

   **Fig. 1**: Binary poor coverage map showing RIS target points (green 'X') and feasible RIS positions (green stars)