Gauss Seidel Method
D
A
def gauss_seidel(
coefficients: list[list[float]],
rhs: list[float],
tol: float = 1e-10,
max_iter: int = 1000,
) -> list[float]:
"""
Solve the linear system Ax = b using the Gauss-Seidel iterative method.
Args:
coefficients (list[list[float]]): Coefficient matrix (n x n)
rhs (list[float]): Right-hand side vector (n)
tol (float): Convergence tolerance
max_iter (int): Maximum number of iterations
Returns:
list[float]: Approximate solution vector
Example:
>>> A = [[4, 1, 2], [3, 5, 1], [1, 1, 3]]
>>> b = [4, 7, 3]
>>> gauss_seidel(A, b)
[0.5, 1.0, 0.5]
Wikipedia:
https://en.wikipedia.org/wiki/Gauss%E2%80%93Seidel_method
"""
n = len(coefficients)
x = [0.0 for _ in range(n)]
for _ in range(max_iter):
x_new = x.copy()
for i in range(n):
sum_before = sum(coefficients[i][j] * x_new[j] for j in range(i))
sum_after = sum(coefficients[i][j] * x[j] for j in range(i + 1, n))
x_new[i] = (rhs[i] - sum_before - sum_after) / coefficients[i][i]
if all(abs(x_new[i] - x[i]) < tol for i in range(n)):
return [round(val, 10) for val in x_new]
x = x_new
return [round(val, 10) for val in x]