# ____________________________________________________________________________________
#
# Pyomo: Python Optimization Modeling Objects
# Copyright (c) 2008-2026 National Technology and Engineering Solutions of Sandia, LLC
# Under the terms of Contract DE-NA0003525 with National Technology and Engineering
# Solutions of Sandia, LLC, the U.S. Government retains certain rights in this
# software. This software is distributed under the 3-clause BSD License.
# ____________________________________________________________________________________
# This software is distributed under the 3-clause BSD License.
# Copied with minor modifications from mpisppy/scenario_tree.py
# from the mpi-sppy library (https://github.com/Pyomo/mpi-sppy).
# ALL INDEXES ARE ZERO-BASED
"""
Note: parmest can make use of mpi-sppy to form the EF so that it could, if it
needed to, solve using a decomposition. To guard against loss of mpi-sppy,
we also have this "local" ability to form the EF.
"""
import pyomo.environ as pyo
[docs]
def build_vardatalist(self, model, varlist=None):
"""
Convert a list of pyomo variables to a list of ScalarVar and VarData. If varlist is none, builds a
list of all variables in the model. The new list is stored in the vars_to_tighten attribute. By CD Laird
Parameters
----------
model: ConcreteModel
varlist: None or list of pyo.Var
"""
vardatalist = None
# if the varlist is None, then assume we want all the active variables
if varlist is None:
raise RuntimeError("varlist is None in scenario_tree.build_vardatalist")
vardatalist = [
v for v in model.component_data_objects(pyo.Var, active=True, sort=True)
]
elif isinstance(varlist, pyo.Var):
# user provided a variable, not a list of variables. Let's work with it anyway
varlist = [varlist]
if vardatalist is None:
# expand any indexed components in the list to their
# component data objects
vardatalist = list()
for v in varlist:
if v.is_indexed():
vardatalist.extend([v[i] for i in sorted(v.keys())])
else:
vardatalist.append(v)
return vardatalist
[docs]
class ScenarioNode:
"""Store a node in the scenario tree.
Note:
This can only be created programmatically from a scenario
creation function. (maybe that function reads data)
Args:
name (str): name of the node; one node must be named "ROOT"
cond_prob (float): conditional probability
stage (int): stage number (root is 1)
cost_expression (pyo Expression or Var): stage cost
scen_name_list (str): OPTIONAL scenario names at the node
just for debugging and reporting; not really used as of Dec 31
nonant_list (list of pyo Var, Vardata or slices): the Vars that
require nonanticipativity at the node (might not be a list)
scen_model (pyo concrete model): the (probably not 'a') concrete model
nonant_ef_suppl_list (list of pyo Var, Vardata or slices):
vars for which nonanticipativity constraints tighten the EF
(important for bundling)
parent_name (str): name of the parent node
Lists:
nonant_vardata(list of vardata objects): vardatas to blend
x_bar_list(list of floats): bound by index to nonant_vardata
"""
[docs]
def __init__(
self,
name,
cond_prob,
stage,
cost_expression,
scen_name_list,
nonant_list,
scen_model,
nonant_ef_suppl_list=None,
parent_name=None,
):
"""Initialize a ScenarioNode object. Assume most error detection is
done elsewhere.
"""
self.name = name
self.cond_prob = cond_prob
self.stage = stage
self.cost_expression = cost_expression
self.nonant_list = nonant_list
self.nonant_ef_suppl_list = nonant_ef_suppl_list
self.parent_name = parent_name # None for ROOT
# now make the vardata lists
if self.nonant_list is not None:
self.nonant_vardata_list = build_vardatalist(
self, scen_model, self.nonant_list
)
else:
print(
"nonant_list is empty for node {},".format(node)
+ "No nonanticipativity will be enforced at this node by default"
)
self.nonant_vardata_list = []
if self.nonant_ef_suppl_list is not None:
self.nonant_ef_suppl_vardata_list = build_vardatalist(
self, scen_model, self.nonant_ef_suppl_list
)
else:
self.nonant_ef_suppl_vardata_list = []