The Real Spherical Harmonics
    Definition: 
      \[ m=0: \qquad Y_{l0}= \sqrt{\frac{2l+1}{4\pi}} \quad P_l^{0} (cos(\theta)) \]
      \[ m>0: \qquad Y_{lm}= (-1)^m \sqrt{2} \sqrt{\frac{2l+1}{4\pi} \frac{(l-m)!}{(l+m)!}} \quad P_l^{m} (cos(\theta)) \quad cos(m \varphi) \]
    
    
      - Choose a representation of the functions from the menu:
        
          - Colored Surface: using a sphere and color it w.r.t value of the function
- Magnitude Mapped: using the magnitude as radii and shape a structure (also colored like the sphere)
 
- Then you can choose l and m.
- The coloring is conected with the value of the function at
          this position:
           
            - red = negativ maximum;
- yellow = Zero;
- green = positiv maximum