GENAC

Introduction

Genac is a symbolic analog circuit analyzer and synthesizer. Given a circuit in a specific netlist form (see samples) it can compute the transfer function of the circuit as a symbolic maths expression using Modified Nodal Analysis (MNA). It can also generate circuits with some certain criteria through genetic algorithms. Genac uses GiNaC to do the symbolic maths for both analyzer and synthesizer modes.

Genac was my final year project at the Department of Electrical and Electronics Engineering, 9 Eylul University. I refactor and improve it in my spare time, so do not expect too much from this project :)

Build

Minimum Qt 5.5.0 required.

sudo apt-get install pkg-config libginac-dev qt5-default cmake
cd to/this/direectory
mkdir build && cd build
cmake ..
make

Run

Run the analyzer:

$ src/genac analyze -n ../samples/circuit1.nl -l ../samples/LIB
*  V(1)
*  ----- =
*  V(4)
*                            R1
*  -------------------------------------------------------
*  R2*s*R3*C2+R2*s*C2*R1+s*R3*C2*R1+C1*R2*s^2*R3*C2*R1+R1

Run genetic algorithm based synthesizer:

$ src/genac genetic-synthesize \
--numerator 001   \
--denominator 111 \
--ncapacitors 2   \
--nresistors 3    \
--active-element OPAMP \
--population-size 15 \
--ngenerations 500 \
--selection-type RANK \
--crossover-type ONEPOINT \
--crossover-probability 0.80 \
--mutation-probability 0.01 # if not provided, defaults to adaptive mutation probability.

Plot genetic algorithm records

Here is an example plot:

./graph.py ~/Documents/ga-circuit-records/different-filters/run1-1/GARecords.txt \
           ~/Documents/ga-circuit-records/different-filters/run2-3/GARecords.txt \
           ~/Documents/ga-circuit-records/different-filters/run3-3/GARecords.txt \
           ~/Documents/ga-circuit-records/different-filters/run4-1/GARecords.txt -f -F -d