Add slice sampling state

pymc/step_methods/slicer.py

@@ -21,7 +21,8 @@
 from pymc.model import modelcontext
 from pymc.pytensorf import compile_pymc, join_nonshared_inputs, make_shared_replacements
 from pymc.step_methods.arraystep import ArrayStepShared
-from pymc.step_methods.compound import Competence
+from pymc.step_methods.compound import Competence, StepMethodState
+from pymc.step_methods.state import dataclass_state
 from pymc.util import get_value_vars_from_user_vars
 from pymc.vartypes import continuous_types
 
@@ -30,6 +31,17 @@
 LOOP_ERR_MSG = "max slicer iters %d exceeded"
 
 
+dataclass_state
+
+
+@dataclass_state
+class SliceState(StepMethodState):
+    w: np.ndarray
+    tune: bool
+    n_tunes: float
+    iter_limit: float
+
+
 class Slice(ArrayStepShared):
     """
     Univariate slice sampler step method.
@@ -61,6 +73,8 @@ class Slice(ArrayStepShared):
         "nstep_in": (int, []),
     }
 
+    _state_class = SliceState
+
     def __init__(
         self, vars=None, w=1.0, tune=True, model=None, iter_limit=np.inf, rng=None, **kwargs
     ):