spicey

Run SPICE simulations in native javascript. An alternative to ngspice


``tsx
import { simulate, formatAcResult } from "spicey"

const net1 =
Demo of a simple AC circuit

v1 1 0 dc 0 ac 1
r1 1 2 30
c1 2 0 100u
.ac dec 100 1 100

.end

const result1 = simulate(net1)

formatAcResult(result1.ac)

"f(Hz), 1:|V|,∠V(deg), 2:|V|,∠V(deg)
1.00000, 1.00000,0.00000, 0.999822,-1.07987
1.02329, 1.00000,0.00000, 0.999814,-1.10502
1.04713, 1.00000,0.00000, 0.999805,-1.13075
1.07152, 1.00000,0.00000, 0.999796,-1.15708
1.09648, 1.00000,0.00000, 0.999786,-1.18403
1.12202, 1.00000,0.00000, 0.999776,-1.21160
1.14815, 1.00000,0.00000, 0.999766,-1.23981
1.17490, 1.00000,0.00000, 0.999755,-1.26868
1.20226, 1.00000,0.00000, 0.999743,-1.29822
..."
)
`

Proposed directory structure

To make it easy to extend the simulator (for example to add transistor models later), the library is now organized into focused modules:

`
lib/
analysis/ # High-level simulation entry points (simulate, simulateAC, simulateTRAN)
constants/ # Shared numeric constants
formatting/ # Result formatting helpers
math/ # Numeric utilities such as Complex arithmetic and matrix solvers
parsing/ # Netlist parsing and circuit data structures
stamping/ # Matrix/RHS stamping helpers for modified nodal analysis
utils/ # Generic helpers (e.g., logarithmic sweeps)
``

Each exported function lives in its own file with a matching name, so new capabilities can be added without creating monolithic modules.