spice3

pip install spice3 → import spice.

Circuit simulation for Python, powered by Dune — a Rust engine derived from Berkeley SPICE3f5 (with BSIM3v3.3, .sp, .measure and several revised routines derived from ngspice-47) and validated circuit-by-circuit against ngspice as numerical oracle.

Status: pre-alpha. This release reserves the package name while the engine's first public version is being finished. The API below works today but may still change.

from pathlib import Path
import spice

result = spice.simulate(Path("rc.cir"))
plot = result.plot("tran")   # or "Transient Analysis"
df = plot.df()               # polars DataFrame, scale column first
df = plot.df("2")            # only v(2): a bare node is its voltage
v2 = plot.column("v(2)")     # zero-copy, read-only numpy array

• Every SPICE3f5 analysis: .op, .dc, .tran, .ac, .pz, .noise, .disto, .tf, .sens — plus the periodic steady state of driven circuits (.pss, shooting–Newton; spice.pss()).
• All SPICE3f5 devices, including BJT (Gummel–Poon), MOS levels 1/2/3/6, BSIM1/BSIM2, JFET, MESFET, switches and both transmission lines.
• Results as polars DataFrames (pandas optional) and zero-copy NumPy arrays; complete type annotations (py.typed).
• Schematics as decks: spice.pic.extract() reads the netlist of an rpic figure drawn with the dune prelude, spice.simulate() runs it and spice.pic.render() draws it as SVG (with typeset $...$ labels).
• Faithful netlist semantics: decks that run under spice3 -b or ngspice -b run here, with structured, span-carrying errors.

The same engine sits under the R package, the JavaScript package, the C library and the command line; a deck gives the same numbers in all of them.

Site: milkway.github.io/dune. Dune repository.

Credits and license

The engine is a derived work: it is translated from SPICE3f5 (© 1985–1991 The Regents of the University of California; Thomas L. Quarles and many others at UC Berkeley) and, for BSIM3v3.3, the .sp analysis, the operating-point fallback chain, .measure, the transient noise sources and the revisions of several device routines, from ngspice-47 (the ngspice team and contributors; BSIM3v3.3.0 by the UC Berkeley BSIM Research Group). The NOTICE file shipped with this package (online) lists the upstream files and reproduces their copyright and licence notices.

Dune is an independent project: it is not affiliated with, sponsored by or endorsed by the University of California, Berkeley, the UC Berkeley BSIM Research Group or the ngspice project. The names "SPICE", "SPICE3" and "ngspice" are used only descriptively, to identify the programs whose netlist language and behaviour Dune implements.

BSD-3-Clause, © André Leite; portions © The Regents of the University of California and the ngspice contributors.