Hi, There seems to be problem with get_edges_prob for the layered SBM. Here is a minimal example: import graph_tool.all as gt import numpy as np gr=gt.generate_sbm(b=np.array([0]*500+[1]*500),probs=np.array([[10000,200],[ 200,10000]])) etype=gr.new_edge_property('int') gr.ep.etype=etype t=0 for e in gr.edges(): gr.ep.etype[e]=t%4 t+=1 state = gt.minimize_nested_blockmodel_dl(gr, deg_corr=True,layers=True,state_args=dict(ec=gr.ep.etype,layers=True)) print(state.get_edges_prob(missing=[[2,32,0]],spurious=[])) print(state.get_edges_prob(missing=[[2,32,0],[3,4,2]],spurious=[])) print(state.get_edges_prob(missing=[[2,32,0],[3,4,2],[36,7,0]],spurious=[])) pr=state.get_edges_prob(missing=[[2,32,0],[3,4,2]],spurious=gr.get_edges([gr .ep.etype])[:3]) Output: 0.0 -7.883180576649465 -7.883180576649465 --------------------------------------------------------------------------- ValueError Traceback (most recent call last) <ipython-input-11-1f73a43d95dd> in <module> 12 print(state.get_edges_prob(missing=[[2,32,0],[3,4,2]],spurious=[])) 13 print(state.get_edges_prob(missing=[[2,32,0],[3,4,2],[36,7,0]],spurious=[])) ---> 14 pr=state.get_edges_prob(missing=[[2,32,0],[3,4,2]],spurious=gr.get_edges([gr .ep.etype])[:3]) /usr/lib/python3/dist-packages/graph_tool/inference/nested_blockmodel.py in get_edges_prob(self, missing, spurious, entropy_args) 499 lstate._state.clear_egroups() 500 --> 501 L += lstate.get_edges_prob(missing, spurious, entropy_args=eargs) 502 if isinstance(self.levels[0], LayeredBlockState): 503 missing = [(lstate.b[u], lstate.b[v], l_) for u, v, l_ in missing] /usr/lib/python3/dist-packages/graph_tool/inference/layered_blockmodel.py in get_edges_prob(self, missing, spurious, entropy_args) 896 if e is None: 897 raise ValueError("edge not found: (%d, %d, %d)" % \ --> 898 (int(u), int(v), l[0])) 899 900 if state.is_weighted: ValueError: edge not found: (3, 4, 2) The error occurs only when spurious edges are included but even without spurious edges the outputs above seem to be inaccurate. I tried to resolve the issue myself but couldn't make it work. Best wishes, Anatol