code: def circular_layout(G, scale=1, center=None, dim=2):
      # dim=2 only
      """Position nodes on a circle.
  
      Parameters
      ----------
      G : NetworkX graph or list of nodes
          A position will be assigned to every node in G.
  
      scale : number (default: 1)
          Scale factor for positions.
  
      center : array-like or None
          Coordinate pair around which to center the layout.
  
      dim : int
          Dimension of layout.
          If dim>2, the remaining dimensions are set to zero
          in the returned positions.
          If dim<2, a ValueError is raised.
  
      Returns
      -------
      pos : dict
          A dictionary of positions keyed by node
  
      Raises
      ------
      ValueError
          If dim < 2
  
      Examples
      --------
      >>> G = nx.path_graph(4)
      >>> pos = nx.circular_layout(G)
  
      Notes
      -----
      This algorithm currently only works in two dimensions and does not
      try to minimize edge crossings.
  
      """
      import numpy as np
  
      if dim < 2:
          raise ValueError("cannot handle dimensions < 2")
  
      G, center = _process_params(G, center, dim)
  
      paddims = max(0, (dim - 2))
  
      if len(G) == 0:
          pos = {}
      elif len(G) == 1:
          pos = {nx.utils.arbitrary_element(G): center}
      else:
          # Discard the extra angle since it matches 0 radians.
          theta = np.linspace(0, 1, len(G) + 1)[:-1] * 2 * np.pi
          theta = theta.astype(np.float32)
          pos = np.column_stack(
              [
                  np.cos(theta),
                  np.sin(theta),
                  np.zeros((len(G), paddims)),
              ]
          )
          pos = rescale_layout(pos, scale=scale) + center
          pos = dict(zip(G, pos))
  
      return pos
  
imports: import networkx
  from networkx.utils import np_random_state
label_desc: Use image node_id 3 for calling a global function with example usage: circular_layout(G, scale, center, dim) and returns: pos