daedalus (Python)

Python API of DAEdalus, a fast Modelica compiler and simulator written in Rust. The compiler runs in-process: no OMC server, no Dymola licence, no files written unless you ask. It covers what scripts usually do with OMPython or Dymola's Python interface: load models, change parameters, simulate, read trajectories as NumPy arrays, linearize, and export FMUs.

import daedalus

m = daedalus.Model("library/Daedalus", "Daedalus.Examples.TorqueConverter.StallTest")
print(m.experiment, m.states)

m.set_parameters({"engine.J": 0.3})          # dotted names: mapping form
r = m.simulate(stop=2.0, n=1000, vars=["rpm_engine", "rpm_stall_theory"])
r.time, r["rpm_engine"]                       # NumPy arrays
df = r.to_pandas()                            # if pandas is installed
r.stats["solver"]["steps"]

lin = daedalus.Model("crates/daedalus-core/tests/models/linearize.mo", "Lin.MassSpringDamper").linearize()
lin.A, lin.B, lin.C, lin.D, lin.states, lin.inputs, lin.outputs

#Install

From a checkout (needs a Rust toolchain):

python -m venv .venv && . .venv/bin/activate
pip install maturin
cd crates/daedalus-py
maturin develop --release          # or: maturin build --release && pip install target/wheels/*.whl
pip install pytest pandas && pytest

The wheel is abi3 (one build for CPython 3.9 and later). The crate is not a member of the cargo workspace, so plain cargo build --workspace does not need Python.

#API

#daedalus.Model(paths, name, *, index_reduction=True, tearing=True)

Loads paths (a path or list of paths: .mo files and library directories, like the positional arguments of the daedalus CLI; a directory with a package.mo is parsed on demand) plus the directories in $DAEDALUS_LIB, and translates model name. Failures raise daedalus.TranslationError with the compiler's message.

Simulation failures raise daedalus.SimulationError; its partial attribute holds the Result up to the failure, if any. Both errors derive from daedalus.DaedalusError.

#daedalus.Result

time (NumPy array), result["x"], names, "x" in result, len(result) (rows), stats (solver steps, rejected steps, f-evals, Jacobians, events, timings), log, final(name), at(name, t), unit(name), description(name), to_dict(), to_pandas(), write_csv(path, names=None), write_mat(path) (Dymola-compatible). daedalus.read_mat(path) reads a .mat result file back.

#daedalus.Linearization

A, B, C, D (2-D NumPy arrays of der(x) = A x + B u, y = C x + D u), states, inputs, outputs, the operating point x0, u0, y0, dx0, time, eigenvalues(), to_modelica() (OpenModelica-style linearized_model), and str(lin) for the text report of daedalus linearize.

#FMU export

The FMU embeds the model-independent FMI runtime library built from crates/daedalus-fmi (cargo build --release -p daedalus-fmi gives target/release/libdaedalus_fmi.so). export_fmu finds it at fmi_lib=, $DAEDALUS_FMI_LIB, inside the installed package, or next to a daedalus executable on PATH.

#Coming from OMPython / Dymola