SensiRho part 1

mpisppy/extensions/sensi_rho.py

@@ -0,0 +1,245 @@
+###############################################################################
+# mpi-sppy: MPI-based Stochastic Programming in PYthon
+#
+# Copyright (c) 2024, Lawrence Livermore National Security, LLC, Alliance for
+# Sustainable Energy, LLC, The Regents of the University of California, et al.
+# All rights reserved. Please see the files COPYRIGHT.md and LICENSE.md for
+# full copyright and license information.
+###############################################################################
+
+import numpy as np
+
+import pyomo.environ as pyo
+from pyomo.contrib.pynumero.interfaces.pyomo_nlp import PyomoNLP
+from pyomo.contrib.pynumero.linalg.base import LinearSolverStatus
+from pyomo.contrib.pynumero.linalg.scipy_interface import ScipyLU
+
+import mpisppy.extensions.extension
+import mpisppy.MPI as MPI
+from mpisppy.utils.kkt.interface import InteriorPointInterface
+
+
+class SensiRho(mpisppy.extensions.extension.Extension):
+    """
+    Rho determination algorithm using nonant sensitivities
+    """
+
+    def __init__(self, ph):
+        self.ph = ph
+
+        self.multiplier = 1.0
+
+        if (
+            "sensi_rho_options" in ph.options
+            and "multiplier" in ph.options["sensi_rho_options"]
+        ):
+            self.multiplier = ph.options["sensi_rho_options"]["multiplier"]
+
+    @staticmethod
+    def _compute_rho_min_max(ph, npop, mpiop, start):
+        local_nodenames = []
+        local_xmaxmin = {}
+        global_xmaxmin = {}
+
+        for k, s in ph.local_scenarios.items():
+            nlens = s._mpisppy_data.nlens
+            for node in s._mpisppy_node_list:
+                if node.name not in local_nodenames:
+                    ndn = node.name
+                    local_nodenames.append(ndn)
+                    nlen = nlens[ndn]
+
+                    local_xmaxmin[ndn] = start * np.ones(nlen, dtype="d")
+                    global_xmaxmin[ndn] = np.zeros(nlen, dtype="d")
+
+        for k, s in ph.local_scenarios.items():
+            nlens = s._mpisppy_data.nlens
+            rho = s._mpisppy_model.rho
+            for node in s._mpisppy_node_list:
+                ndn = node.name
+                xmaxmin = local_xmaxmin[ndn]
+
+                xmaxmin_partial = np.fromiter(
+                    (rho[ndn,i]._value for i, _ in enumerate(node.nonant_vardata_list)),
+                    dtype="d",
+                    count=nlens[ndn],
+                )
+                xmaxmin = npop(xmaxmin, xmaxmin_partial)
+                local_xmaxmin[ndn] = xmaxmin
+
+        for nodename in local_nodenames:
+            ph.comms[nodename].Allreduce(
+                [local_xmaxmin[nodename], MPI.DOUBLE],
+                [global_xmaxmin[nodename], MPI.DOUBLE],
+                op=mpiop,
+            )
+
+        xmaxmin_dict = {}
+        for ndn, global_xmaxmin_dict in global_xmaxmin.items():
+            for i, v in enumerate(global_xmaxmin_dict):
+                xmaxmin_dict[ndn, i] = v
+
+        return xmaxmin_dict
+
+    @staticmethod
+    def _compute_rho_avg(ph):
+        local_nodenames = []
+        local_avg = {}
+        global_avg = {}
+
+        for k, s in ph.local_scenarios.items():
+            nlens = s._mpisppy_data.nlens
+            rho = s._mpisppy_model.rho
+            for node in s._mpisppy_node_list:
+                if node.name not in local_nodenames:
+                    ndn = node.name
+                    local_nodenames.append(ndn)
+                    nlen = nlens[ndn]
+
+                    local_avg[ndn] = np.zeros(nlen, dtype="d")
+                    global_avg[ndn] = np.zeros(nlen, dtype="d")
+
+        for k, s in ph.local_scenarios.items():
+            nlens = s._mpisppy_data.nlens
+            rho = s._mpisppy_model.rho
+            for node in s._mpisppy_node_list:
+                ndn = node.name
+
+                local_rhos = np.fromiter(
+                        (rho[ndn,i]._value for i, _ in enumerate(node.nonant_vardata_list)),
+                        dtype="d",
+                        count=nlens[ndn],
+                    )
+                # print(f"{k=}, {local_rhos=}, {s._mpisppy_probability=}, {s._mpisppy_data.prob_coeff[ndn]=}")
+                # TODO: is this the right thing, or should it be s._mpisppy_probability?
+                local_rhos *= s._mpisppy_data.prob_coeff[ndn]
+
+                local_avg[ndn] += local_rhos
+
+        for nodename in local_nodenames:
+            ph.comms[nodename].Allreduce(
+                [local_avg[nodename], MPI.DOUBLE],
+                [global_avg[nodename], MPI.DOUBLE],
+                op=MPI.SUM,
+            )
+
+        rhoavg_dict = {}
+        for ndn, global_rhoavg_dict in global_avg.items():
+            for i, v in enumerate(global_rhoavg_dict):
+                rhoavg_dict[ndn, i] = v
+
+        return rhoavg_dict
+
+    @staticmethod
+    def _compute_rho_max(ph):
+        return SensiRho._compute_rho_min_max(ph, np.maximum, MPI.MAX, -np.inf)
+
+    @staticmethod
+    def _compute_rho_min(ph):
+        return SensiRho._compute_rho_min_max(ph, np.minimum, MPI.MIN, np.inf)
+
+    def pre_iter0(self):
+        pass
+
+    def post_iter0(self):
+        ph = self.ph
+
+        # first, solve the subproblems with Ipopt,
+        # and gather sensitivity information
+        ipopt = pyo.SolverFactory("ipopt")
+        nonant_sensis = {}
+        for k, s in ph.local_subproblems.items():
+            solution_cache = pyo.ComponentMap()
+            for var in s.component_data_objects(pyo.Var):
+                solution_cache[var] = var._value
+            relax_int = pyo.TransformationFactory('core.relax_integer_vars')
+            relax_int.apply_to(s)
+
+            assert hasattr(s, "_relaxed_integer_vars")
+
+            # add the needed suffixes / remove later
+            s.ipopt_zL_out = pyo.Suffix(direction=pyo.Suffix.IMPORT)
+            s.ipopt_zU_out = pyo.Suffix(direction=pyo.Suffix.IMPORT)
+            s.dual = pyo.Suffix(direction=pyo.Suffix.IMPORT_EXPORT)
+
+            results = ipopt.solve(s)
+            pyo.assert_optimal_termination(results)
+
+            kkt_builder = InteriorPointInterface(s)
+            kkt_builder.set_barrier_parameter(1e-9)
+            kkt_builder.set_bounds_relaxation_factor(1e-8)
+            #rhs = kkt_builder.evaluate_primal_dual_kkt_rhs()
+            #print(f"{rhs}")
+            #print(f"{rhs.flatten()}")
+            kkt = kkt_builder.evaluate_primal_dual_kkt_matrix()
+
+            # print(f"{kkt=}")
+            # could do better than SuperLU
+            kkt_lu = ScipyLU()
+            # always regularize equality constraints
+            kkt_builder.regularize_equality_gradient(kkt=kkt, coef=-1e-8, copy_kkt=False)
+            kkt_lu.do_numeric_factorization(kkt, raise_on_error=True)
+
+            grad_vec = np.zeros(kkt.shape[1])
+            grad_vec[0:kkt_builder._nlp.n_primals()] = kkt_builder._nlp.evaluate_grad_objective()
+
+            grad_vec_kkt_inv = kkt_lu._lu.solve(grad_vec, "T")
+
+            for scenario_name in s.scen_list:
+                nonant_sensis[scenario_name] = {}
+                rho = ph.local_scenarios[scenario_name]._mpisppy_model.rho
+                for ndn_i, v in ph.local_scenarios[scenario_name]._mpisppy_data.nonant_indices.items():
+                    var_idx = kkt_builder._nlp._vardata_to_idx[v]
+
+                    y_vec = np.zeros(kkt.shape[0])
+                    y_vec[var_idx] = 1.0
+
+                    x_denom = y_vec.T @ kkt_lu._lu.solve(y_vec)
+                    x = (-1 / x_denom)
+                    e_x = x * y_vec
+
+                    sensitivity = grad_vec_kkt_inv @ -e_x
+                    # print(f"df/d{v.name}: {sensitivity:.2e}, ∂f/∂{v.name}: {grad_vec[var_idx]:.2e}, "
+                    #       f"rho {v.name}: {ph.local_scenarios[scenario_name]._mpisppy_model.rho[ndn_i]._value:.2e}, ",
+                    #       f"value: {v._value:.2e}"
+                    #       )
+
+                    rho[ndn_i]._value = abs(sensitivity)
+
+            relax_int.apply_to(s, options={"undo":True})
+            assert not hasattr(s, "_relaxed_integer_vars")
+            del s.ipopt_zL_out
+            del s.ipopt_zU_out
+            del s.dual
+            for var, val in solution_cache.items():
+                var._value = val
+
+        for s in ph.local_scenarios.values():
+            xbars = s._mpisppy_model.xbars
+            for ndn_i, rho in s._mpisppy_model.rho.items():
+                nv = s._mpisppy_data.nonant_indices[ndn_i]  # var_data object
+                rho._value = rho._value / max(1, abs(nv._value - xbars[ndn_i]._value))
+                rho._value *= self.multiplier
+                # if ph.cylinder_rank == 0:
+                #     print(f"{s.name=}, {nv.name=}, {rho.value=}")
+
+        rhoavg = self._compute_rho_avg(ph)
+        for s in ph.local_scenarios.values():
+            xbars = s._mpisppy_model.xbars
+            for ndn_i, rho in s._mpisppy_model.rho.items():
+                rho._value = rhoavg[ndn_i]
+                # if ph.cylinder_rank == 0:
+                #     nv = s._mpisppy_data.nonant_indices[ndn_i]  # var_data object
+                #     print(f"{s.name=}, {nv.name=}, {rho.value=}")
+
+        if ph.cylinder_rank == 0:
+            print("Rho values updated by SensiRho Extension")
+
+    def miditer(self):
+        pass
+
+    def enditer(self):
+        pass
+
+    def post_everything(self):
+        pass

mpisppy/generic_cylinders.py

@@ -72,6 +72,7 @@ def _parse_args(m):
     cfg.reduced_costs_args()
     cfg.sep_rho_args()
     cfg.coeff_rho_args()
+    cfg.sensi_rho_args()
 
     cfg.parse_command_line(f"mpi-sppy for {cfg.module_name}")
     return cfg
@@ -99,7 +100,7 @@ def _name_lists(module, cfg):
 def _do_decomp(module, cfg, scenario_creator, scenario_creator_kwargs, scenario_denouement):
     rho_setter = module._rho_setter if hasattr(module, '_rho_setter') else None
     if cfg.default_rho is None and rho_setter is None:
-        if cfg.sep_rho or cfg.coeff_rho:
+        if cfg.sep_rho or cfg.coeff_rho or cfg.sensi_rho:
             cfg.default_rho = 1
         else:
             raise RuntimeError("No rho_setter so a default must be specified via --default-rho")
@@ -167,6 +168,9 @@ def _do_decomp(module, cfg, scenario_creator, scenario_creator_kwargs, scenario_
 
     if cfg.coeff_rho:
         vanilla.add_coeff_rho(hub_dict, cfg)
+
+    if cfg.sensi_rho:
+        vanilla.add_sensi_rho(hub_dict, cfg)
 
     if len(ext_classes) != 0:
         hub_dict['opt_kwargs']['extensions'] = MultiExtension
@@ -215,6 +219,9 @@ def _do_decomp(module, cfg, scenario_creator, scenario_creator_kwargs, scenario_
             vanilla.add_sep_rho(ph_ob_spoke, cfg)
         if cfg.coeff_rho:
             vanilla.add_coeff_rho(ph_ob_spoke, cfg)
+        if cfg.sensi_rho:
+            vanilla.add_sensi_rho(ph_ob_spoke, cfg)
+
 
     # subgradient outer bound spoke
     if cfg.subgradient:
@@ -227,6 +234,8 @@ def _do_decomp(module, cfg, scenario_creator, scenario_creator_kwargs, scenario_
             vanilla.add_sep_rho(subgradient_spoke, cfg)
         if cfg.coeff_rho:
             vanilla.add_coeff_rho(subgradient_spoke, cfg)
+        if cfg.sensi_rho:
+            vanilla.add_sensi_rho(subgradient_spoke, cfg)
 
     # xhat shuffle bound spoke
     if cfg.xhatshuffle:

mpisppy/utils/cfg_vanilla.py

@@ -42,6 +42,7 @@
 from mpisppy.extensions.reduced_costs_fixer import ReducedCostsFixer
 from mpisppy.extensions.sep_rho import SepRho
 from mpisppy.extensions.coeff_rho import CoeffRho
+from mpisppy.extensions.sensi_rho import SensiRho
 from mpisppy.utils.wxbarreader import WXBarReader
 from mpisppy.utils.wxbarwriter import WXBarWriter
 
@@ -209,6 +210,10 @@ def add_coeff_rho(hub_dict, cfg):
     hub_dict = extension_adder(hub_dict,CoeffRho)
     hub_dict["opt_kwargs"]["options"]["coeff_rho_options"] = {"multiplier" : cfg.coeff_rho_multiplier}
 
+def add_sensi_rho(hub_dict, cfg):
+    hub_dict = extension_adder(hub_dict,SensiRho)
+    hub_dict["opt_kwargs"]["options"]["sensi_rho_options"] = {"multiplier" : cfg.sensi_rho_multiplier}
+
 def add_cross_scenario_cuts(hub_dict,
                             cfg,
                             ):

mpisppy/utils/config.py

@@ -421,6 +421,17 @@ def sep_rho_args(self):
                            default=1.0)
 
 
+    def sensi_rho_args(self):
+        self.add_to_config("sensi_rho",
+                           description="have a SensiRho extension",
+                           domain=bool,
+                           default=False)
+        self.add_to_config("sensi_rho_multiplier",
+                           description="multiplier for SensiRho (default 1.0)",
+                           domain=float,
+                           default=1.0)
+
+
     def coeff_rho_args(self):
         self.add_to_config("coeff_rho",
                            description="have a CoeffRho extension",