#<img src="http://raw.github.com/wiki/ahkab/ahkab/images/logo_small.png" alt="Monkeying around" style="width: 80px;"/> ahkab
***a SPICE-like electronic circuit simulator written in Python***
The code should be easy to read and modify, the main language is Python 2.x and it is platform-independent.[](http://githalytics.com/ahkab/ahkab)
### News! ###
* The whole codebase has been going through a (yet incomplete) refactoring and documenting thorough effort.
* Tests have been added to the code base, to weed out bugs and have a consistent way to check for regressions. If you have tests you would like to suggest, please send a PR my way.
* My resources are limited these days, so the much-needed work is proceeding slowly, albeit hopefully steadily. If you are interested and you would like to contribute to refactoring or documenting a particular feature, it would be very welcome.
[](https://travis-ci.org/ahkab/ahkab) [](https://coveralls.io/r/ahkab/ahkab?branch=master)
[](https://pypi.python.org/pypi/ahkab/) [](https://raw.githubusercontent.com/ahkab/ahkab/master/LICENSE)
<!--- [](https://pypi.python.org/pypi/ahkab/) --->
### Supported simulations: ###
* Numeric:
* **Operating point**, with guess computation to speed up the solution. See example: [Downscaling current mirror](https://github.com/ahkab/ahkab/wiki/Example:-OP-simulation)
* **DC sweep**
* **Transient analysis**, available differentiation formulas: implicit Euler, trapezoidal, gear orders from 2 to 5. See for example the [simulation of a Colpitts Oscillator](https://github.com/ahkab/ahkab/wiki/Example:-Transient-simulation-1).
* **AC analysis**
* **Periodic steady state analysis** of non-autonomous circuits, _time_ _domain_ shooting and brute-force algorithms.
* Symbolic:
* **Small signal analysis**, AC or DC, with extraction of transfer functions, DC gain, poles and zeros. Various [symbolic analysis examples on this page](https://github.com/ahkab/ahkab/wiki/Example:-Symbolic-simulation).
The results are saved to disk, plotted or printed to stdout and can be read/processed by the most common tools (eg. [Octave](http://www.gnu.org/software/octave/), [gnuplot](http://www.gnuplot.info/), [Matlab](http://www.mathworks.com/products/matlab/), [gwave](http://www.telltronics.org/software/gwave/) and others)
###Download and install###
There are no packages for the time being (this program is at an early development stage). Go to [ahkab on github](https://github.com/ahkab/ahkab) and follow the instructions to check out the code. You can find the list of the dependencies in the [Install notes](https://github.com/ahkab/ahkab/wiki/Install:-Notes).
###Usage###
* `ahkab` can be run _within Python scripts as a library_. This will likely become the preferred way in the future. See **[this butterworth filter simulation](https://github.com/ahkab/ahkab/wiki/Example:-Python-API)** for an example/tentative tutorial.
* or stand-alone with a netlist file, the syntax being:
`$ python ahkab -o graph.dat <netlist file>`
See `ahkab --help` for command line switches.
###Documentation###
The simulator can either be run from the command line with a netlist file or included in a python script. Both possibilities will be maintained for the foreseeable future.
Refer to the [netlist syntax page](https://github.com/ahkab/ahkab/wiki/Help:-Netlist-Syntax) for how to write the netlist files that describe the circuit. Experience with running SPICE or other commercial simulators can be useful.
The latter option is shown briefly in the **[Python API](https://github.com/ahkab/ahkab/wiki/Example:-Python-API)** wiki page. The code comes with docstrings associated with _most_ functions, type `help(ahkab.function_name)`.
### How this project was born ###
This project was born when I was an enthusistic undergrad, apparently with plenty of free time, attending "Simulazione Circuitale" (*Circuit Simulation*) taught by [Prof. A. Brambilla](http://brambilla.dei.polimi.it/) back in Italy at the Polytechnic University of Milan.
I am grateful to prof. Brambilla for teaching one of the most interesting courses of my university years. -GV
### Contributors ###
[Giuseppe Venturini](https://github.com/ggventurini), [Ian Daniher](https://github.com/itdaniher), [Rob Crowther](https://github.com/weilawei).
### Bugs and patches ###
Note that _I often add new functionality at the expense of breaking stuff_. Most likely I will introduce a new feature even if that means breaking a couple of others. It should get fixed soon, but if you have a bit of time to spare, you can send me a pull request or a patch. :)
Does it work? Bugs? Do you have patches? Did you run some noteworthy simulation? Let me know! Feedback is very welcome, my [email address](http://tinymailto.com/5310) is available after a captcha.
