>>> # Instantiate a graph>>> g=dgl.graph((torch.tensor([0,1,1]),torch.tensor([1,1,0])))>>> g.ndata['h']=torch.ones(2,1)
>>> # Define a UDF that computes the sum of the messages received for each node>>> # and increments the result by 1>>> defnode_udf(nodes):>>> return{'h':torch.ones(nodes.batch_size(),1)+nodes.mailbox['m'].sum(1)}
>>> # Use node UDF in message passing>>> importdgl.functionasfn>>> g.update_all(fn.copy_u('h','m'),node_udf)>>> g.ndata['h']tensor([[2.], [3.]])