Pips interface

cvxpy/__init__.py

@@ -106,6 +106,7 @@
     HIGHS as HIGHS,
     IPOPT as IPOPT,
     KNITRO as KNITRO,
+    PIPS as PIPS,
     get_num_threads as get_num_threads,
     set_num_threads as set_num_threads,
 )

cvxpy/problems/problem.py

@@ -49,6 +49,7 @@
 from cvxpy.reductions.solvers.conic_solvers.conic_solver import ConicSolver
 from cvxpy.reductions.solvers.defines import SOLVER_MAP_CONIC, SOLVER_MAP_QP
 from cvxpy.reductions.solvers.nlp_solvers.ipopt_nlpif import IPOPT as IPOPT_nlp
+from cvxpy.reductions.solvers.nlp_solvers.pips_nlpif import PIPS as PIPS_nlp
 from cvxpy.reductions.solvers.qp_solvers.qp_solver import QpSolver
 from cvxpy.reductions.solvers.solver import Solver
 from cvxpy.reductions.solvers.solving_chain import (
@@ -1219,8 +1220,13 @@ def _solve(self,
                                                                 verbose, solver_opts=kwargs)
                 self.unpack_results(solution, smooth_chain, inverse_data)
             else:
-                nlp_reductions = reductions + [Expr2Smooth(smooth_approx=False),
-                                                                    IPOPT_nlp()]
+                nlp_reductions = reductions + [Expr2Smooth(smooth_approx=False)]
+                if solver is None:
+                    nlp_reductions += [IPOPT_nlp()]
+                elif solver.upper() == 'IPOPT':
+                    nlp_reductions += [IPOPT_nlp()]
+                elif solver.upper() == 'PIPS':
+                    nlp_reductions += [PIPS_nlp()]
                 nlp_chain = SolvingChain(reductions=nlp_reductions)
                 problem, inverse_data = nlp_chain.apply(problem=self)
                 solution = nlp_chain.solver.solve_via_data(problem, warm_start,

cvxpy/reductions/solvers/defines.py

@@ -47,6 +47,7 @@
 from cvxpy.reductions.solvers.conic_solvers.sdpa_conif import SDPA as SDPA_con
 from cvxpy.reductions.solvers.conic_solvers.xpress_conif import XPRESS as XPRESS_con
 from cvxpy.reductions.solvers.nlp_solvers.ipopt_nlpif import IPOPT as IPOPT_nlp
+from cvxpy.reductions.solvers.nlp_solvers.pips_nlpif import PIPS as PIPS_nlp
 
 # QP interfaces
 from cvxpy.reductions.solvers.qp_solvers.copt_qpif import COPT as COPT_qp
@@ -84,7 +85,7 @@
                   MPAX_qp(),
                   KNITRO_qp(),
                   ]
-solver_nlp_intf = [IPOPT_nlp()]
+solver_nlp_intf = [IPOPT_nlp(), PIPS_nlp()]
 
 SOLVER_MAP_CONIC = {solver.name(): solver for solver in solver_conic_intf}
 SOLVER_MAP_QP = {solver.name(): solver for solver in solver_qp_intf}
@@ -111,7 +112,7 @@
               s.DAQP,
               s.MPAX,
               s.KNITRO]
-NLP_SOLVERS = [s.IPOPT]
+NLP_SOLVERS = [s.IPOPT, s.PIPS]
 DISREGARD_CLARABEL_SDP_SUPPORT_FOR_DEFAULT_RESOLUTION = True
 MI_SOLVERS = [s.GLPK_MI, s.MOSEK, s.GUROBI, s.CPLEX,
               s.XPRESS, s.CBC, s.SCIP, s.HIGHS, s.COPT,