Calculate node voltages from a netlist

nodevoltage.jl

using LinearAlgebra

@enum Element Resistor Voltage Current

netlist = [
    (0, 1, Resistor, 4),
    (0, 1, Current, 6),
    (0, 2, Resistor, 6),
    (0, 3, Resistor, 8),
    (1, 2, Resistor, 3),
    (1, 3, Resistor, 6),
    (1, 3, Current, 4),
    (2, 3, Resistor, 5),
]
dim = 3

admitance = zeros(dim, dim)
current = zeros(dim)

for (n1, n2, typ, val) in netlist
    if typ == Resistor
        if n1 > 0
            admitance[n1, n1] += 1/val
        end
        if n2 > 0
            admitance[n2, n2] += 1/val
        end
        if n1 > 0 && n2 > 0
            admitance[n1, n2] -= 1/val
            admitance[n2, n1] -= 1/val
        end
    elseif typ == Current
        if n1 > 0
            current[n1] -= val
        end
        if n2 > 0
            current[n2] += val
        end
    end
end
println(admitance)
println(current)
voltages = inv(admitance)*current
println(voltages)