pyomo-pounce 0.4.0

Pyomo solver plugin for the POUNCE interior-point NLP solver

pyomo-pounce

Pyomo solver plugin for POUNCE, a pure-Rust interior-point NLP solver (a Rust port of IPOPT).

POUNCE speaks the AMPL NL/SOL protocol, so Pyomo drives it through the AMPL Solver Library interface — exactly how Pyomo integrates with IPOPT.

Installation

pip install pyomo-pounce

That single command pulls in the pounce-solver dependency, which ships a per-platform wheel bundling the pounce executable. After install, pounce is on your PATH and Pyomo finds it automatically.

Usage

import pyomo_pounce  # registers the solver
from pyomo.environ import *

model = ConcreteModel()
model.x = Var(initialize=0.5)
model.obj = Objective(expr=(model.x - 2)**2)

solver = SolverFactory('pounce')
result = solver.solve(model, tee=True)
print(f"x* = {value(model.x)}")  # 2.0

Solver Options

Pass options the same way as IPOPT:

solver = SolverFactory('pounce')
solver.options['max_iter'] = 1000
solver.options['tol'] = 1e-10
solver.options['print_level'] = 5

Options are forwarded to POUNCE's OptionsList (ipopt.opt-compatible keys).

Local development / unsupported platforms

If pounce-solver does not ship a wheel for your platform, the pip install fails on the dependency. Two workarounds:

1. Build POUNCE from source and put it on PATH — the plugin resolves pounce via shutil.which, so any binary on PATH works:

   # in the pounce repo
   cargo build --release --bin pounce
   export PATH="$PWD/target/release:$PATH"
   pip install --no-deps pyomo-pounce pyomo
   

2. Install pounce-solver from source via maturin:

   cd pounce/python && maturin develop --release
   # then `cargo install --path ../crates/pounce-cli` to get the CLI
   # since maturin develop does not bundle the binary.
   pip install pyomo-pounce
   

License

EPL-2.0, same as POUNCE.