Update pymc/step_methods/metropolis.py

Co-authored-by: Ricardo Vieira <[email protected]>

Author: jessegrabowski

pymc/step_methods/metropolis.py

@@ -308,7 +308,7 @@ def astep(self, q0: RaveledVars) -> tuple[RaveledVars, StatsType]:
         else:
             accept_rate = self.delta_logp(q, q0d)
             q, accepted = metrop_select(accept_rate, q, q0d, rng=self.rng)
-            self.accept_rate_iter[:] = accept_rate
+            self.accept_rate_iter[0] = accept_rate
             self.accepted_iter[0] = accepted
             self.accepted_sum += accepted