code: def triangular_coord(coord):
      
      unitvec = np.array([[1, 0], [0.5, math.sqrt(3) / 2]])
      result = np.dot(np.array(coord), unitvec)
      return result.transpose()
docs: Convert a 2D coordinate into a triangle-based coordinate system for a
      prettier phase diagram.
  
      Args:
          coordinate: coordinate used in the convex hull computation.
  
      Returns:
          coordinates in a triangular-based coordinate system.