Error in mcmc_sweep() in network reconstruction

Cross-posted from the discourse per request:

Hi,

I’m on a fresh install of graph-tool (v2.72) on Pop!_OS 22.04 and I’m encountering an issue trying to run some of the example code from the documentation, specifically the Reconstruction with synthetic data examples.

The code I am executing is essentially verbatim from the docs:

import graph_tool.all as gt
import numpy as np


g = gt.collection.data["dolphins"]
E = g.num_edges()
N = g.num_vertices()
w = g.new_ep("double", vals=np.random.normal(N/(2*E), .05, E))  # True edge weights
istate = gt.IsingGlauberState(g, w=w)

M = 1000
X = []
for m in range(M):
    istate.iterate_sync()
    X.append(istate.get_state().a.copy())
X = np.array(X).T

state = gt.IsingGlauberBlockState(X)

for i in range(10):
    delta, *_ = state.mcmc_sweep(niter=10)
    print(delta)

While from the docs I expect this to return the list of deltas, I instead encounter the following:

---------------------------------------------------------------------------
AxisError                                 Traceback (most recent call last)
Cell In[2], line 21
     18 state = gt.IsingGlauberBlockState(X)
     20 for i in range(10):
---> 21     delta, *_ = state.mcmc_sweep(niter=10)
     22     print(delta)

File ~/anaconda3/envs/gt/lib/python3.12/site-packages/graph_tool/inference/reconstruction.py:442, in DynamicsBlockStateBase.mcmc_sweep(self, beta, niter, edge, edge_swap, edge_multiflip, theta, theta_multiflip, sbm, xvals, tvals, k, keep_elist, verbose, elist_args, edge_mcmc_args, edge_swap_mcmc_args, edge_multiflip_mcmc_args, xvals_mcmc_args, theta_mcmc_args, theta_multiflip_mcmc_args, tvals_mcmc_args, sbm_mcmc_args, **kwargs)
    440             if verbose:
    441                 print("tvals_sweep:")
--> 442             eret = self.tvals_sweep(**dict(dict(beta=beta,
    443                                                 niter=10 * niter,
    444                                                 **kwargs),
    445                                            **tvals_mcmc_args))
    446             ret = (sum(x) for x in zip(ret, eret))
    447 if edge:

File ~/anaconda3/envs/gt/lib/python3.12/site-packages/graph_tool/inference/base_states.py:79, in mcmc_sweep_wrap.<locals>.wrapper(self, *args, **kwargs)
     76         assert self._check_clabel(), "invalid clabel before sweep"
     77     Si = self.entropy(**entropy_args)
---> 79 ret = func(self, *args, **kwargs)
     81 if _bm_test() and test:
     82     if hasattr(self, "_check_clabel"):

File ~/anaconda3/envs/gt/lib/python3.12/site-packages/graph_tool/inference/reconstruction.py:935, in DynamicsBlockStateBase.tvals_sweep(self, beta, niter, maxiter, min_size, tol, entropy_args)
    905 r"""Perform sweeps of a greedy update on the node category
    906 values, based on bisection search.
    907 
   (...)
    931     Number of variables moved.
    932 """
    934 tvals = self.get_tvals()
--> 935 r = min(niter/len(tvals), 1) if len(tvals) > 0 else 1
    936 niter = max(1, int(round(niter/len(tvals)))) if len(tvals) > 0 else 1
    937 ea = self._get_entropy_args(entropy_args)

File ~/anaconda3/envs/gt/lib/python3.12/site-packages/numpy/_core/fromnumeric.py:3042, in min(a, axis, out, keepdims, initial, where)
   2925 @array_function_dispatch(_min_dispatcher)
   2926 def min(a, axis=None, out=None, keepdims=np._NoValue, initial=np._NoValue,
   2927         where=np._NoValue):
   2928     """
   2929     Return the minimum of an array or minimum along an axis.
   2930 
   (...)
   3040     6
   3041     """
-> 3042     return _wrapreduction(a, np.minimum, 'min', axis, None, out,
   3043                           keepdims=keepdims, initial=initial, where=where)

File ~/anaconda3/envs/gt/lib/python3.12/site-packages/numpy/_core/fromnumeric.py:86, in _wrapreduction(obj, ufunc, method, axis, dtype, out, **kwargs)
     83         else:
     84             return reduction(axis=axis, out=out, **passkwargs)
---> 86 return ufunc.reduce(obj, axis, dtype, out, **passkwargs)

AxisError: axis 1 is out of bounds for array of dimension 0

The same error also gets thrown for mcmc_sweep() call in the subsequent example for empirical data.