# kirchhoff_exercise_01.py
# This script solves a simple LES resulting from Kirchhoff's laws.
# Example from NunezPhysics video tutorial: https://www.youtube.com/watch?v=zdE7xsbuNTg
# R. Becker, 2021-10-23 

import numpy as np

# A matrix is an array of rows, which are arrays. Thus a matrix is a two dimensional array.
# The numpy.array() function is used to create 2D array (aka matrix) from a list of row lists.
R = np.array(
    [
        [-1.0, -1.0,  1.0],
        [-6.0,  3.0,  0.0],
        [ 0.0, -3.0, -6.0]
    ])

V = np.array([0.0, -24.0, -12.0])

# Inverse matrix
Rinv = np.linalg.inv(R)

# Matrix vector multiplication, aka dot product
I = Rinv.dot(V)

# Print currents
print(I)