WUT_Computer_Science/code/matrix_generator.py
2024-11-17 17:45:23 +01:00

57 lines
2.0 KiB
Python

import numpy as np
import scipy.io
class MatrixGenerator:
@staticmethod
def generate_spd_matrix(n: int) -> np.ndarray:
"""
Generates a random symmetric positive definite matrix of size n x n.
Parameters:
n (int): The size of the matrix to generate.
Returns:
np.ndarray: A symmetric positive definite matrix of size n x n.
"""
A = np.random.rand(n, n)
spd_matrix = np.dot(A, A.T) + n * np.eye(n) # Adding n*I ensures positive definiteness
return spd_matrix
@staticmethod
def generate_identity_matrix(size):
return np.eye(size)
@staticmethod
def generate_alternating_vector(size):
return np.tile([1, 2], int(np.ceil(size / 2)))[:size]
@staticmethod
def get_matrix_from_file(file_path, problem):
mat_contents = scipy.io.loadmat(file_path)
problem_record = mat_contents['Problem'][0][0]
A = problem_record[problem]
if scipy.sparse.issparse(A):
A_dense = A.todense()
else:
A_dense = A
return np.array(A_dense)
@staticmethod
def generate_matrix_and_vector(type, size=None):
if type == 'spd':
if size is None:
raise ValueError("Size must be provided for SPD matrix generation.")
matrix = MatrixGenerator.generate_spd_matrix(size)
vector = np.random.uniform(-1, 1, size)
elif type == 'nemeth12':
matrix = -1 * MatrixGenerator.get_matrix_from_file("nemeth12.mat", 1)
size = matrix.shape[0]
vector = MatrixGenerator.generate_alternating_vector(size)
elif type == 'poli3':
matrix = MatrixGenerator.get_matrix_from_file("poli3.mat", 2)
size = matrix.shape[0]
vector = MatrixGenerator.generate_alternating_vector(size)
else:
raise ValueError("Invalid type specified. Choose 'spd', 'nemeth12', or 'poli3'.")
return matrix, vector