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

---------------------------------------------------------------------------

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