InSpice

This repository has been forked from it's original repository PySpice.

About

InSpice is a Python interface to the Ngspice and Xyce circuit simulators. It provides a Python API to describe electronic circuits and to run analog simulations.

Installation

You can install InSpice from PyPI:

pip install inspice

For development installation:

git clone https://github.com/Innovoltive/InSpice.git
cd InSpice
pip install -e .

Dependencies

• Python >= 3.12
• Ngspice (as shared library)
• matplotlib (for plotting)
• numpy (for numerical computation)

Usage

See the examples directory for various examples of using InSpice.

Basic example:

import InSpice
from InSpice.Unit import *

circuit = InSpice.Circuit('Simple RC Circuit')
circuit.R('1', 'input', 'output', 1@kΩ)
circuit.C('1', 'output', circuit.gnd, 1@µF)

Backend-specific include options

Circuit.include() and Circuit.lib() accept extra keyword arguments for the target simulator's include directive. For example, a parser-enabled VACASK build can load SPICE libraries directly:

from InSpice.Spice.Netlist import Circuit
from InSpice.Spice.Simulator import Simulator

circuit = Circuit('Foreign model libraries')
circuit.include('native-models.lib')
circuit.include('ngspice-models.lib', lang='ngspice')
circuit.lib('xyce-corners.lib', 'tt', lang='xyce')

simulation = Simulator.factory(simulator='vacask').simulation(circuit)
simulation.operating_point(run=False)
print(simulation)

The foreign directives become include "/absolute/path/ngspice-models.lib" lang=ngspice and include "/absolute/path/xyce-corners.lib" lang=xyce section=tt. VACASK supports lang and section options as bare identifiers; unsupported options or values raise ValueError during serialization. Analysis commands remain in the native VACASK control block.

Calls without extra options retain their existing behavior. Options participate in duplicate detection and are preserved by Circuit.clone() and Circuit.copy_to(). Generating ordinary SPICE output (including ngspice and Xyce output) with extra options raises ValueError, rather than silently dropping them. The caller chooses options appropriate to the target; InSpice does not infer a dialect from a path.

Documentation

For detailed documentation, please refer to the examples and docstrings.

License

InSpice is licensed under the GNU General Public License v3.0 (GPL-3.0), the same license as the original PySpice project.

GNU GPL v3.0

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Acknowledgments

Original project (PySpice) by Fabrice Salvaire

Copyright (C) 2025 Innovoltive

Modified by Innovoltive on April 18, 2025.