100 lines
2.4 KiB
Python
100 lines
2.4 KiB
Python
import math
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from typing import List
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from tabulate import tabulate
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def matmul(matrix_a:List[List[float]], matrix_b:List[List[float]]) -> List[List[float]]:
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"""
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calculates matrix multiplication with 2 matrices
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:param matrix_a: the first matrix
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:param matrix_b: the second matrix
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:return: the product of 2 matrices
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"""
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a_rows = len(matrix_a)
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a_columns = len(matrix_a[0])
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b_rows = len(matrix_b)
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b_columns = len(matrix_b[0])
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if not a_columns == b_rows:
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raise ValueError("Matrices not valid")
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result = []
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for i in range(a_rows):
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line = []
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for j in range(b_columns):
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elem = 0
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for k in range(a_columns):
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elem += matrix_a[i][k] * matrix_b[k][j]
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line.append(elem)
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result.append(line)
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return result
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def transpose(matrix:List[List[int]]) -> List[List[int]]:
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"""
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transposes the matrix
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:param matrix: the matrix
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:return: the transpose of the matrix
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"""
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if not matrix:
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raise ValueError("Matrices not valid")
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rows = len(matrix)
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cols = len(matrix[0])
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#for i in matrix:
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# if rows != cols:
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# raise ValueError("Matrices not valid")
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result = []
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for i in range(cols):
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line = []
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for j in range(rows):
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line.append(matrix[j][i])
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result.append(line)
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return result
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def rot_2D(angle: float) -> List[List[float]]:
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rot_matrix = [[math.cos(angle), -math.sin(angle)],
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[math.sin(angle), math.cos(angle)]]
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return rot_matrix
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if __name__ == "__main__":
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# created by ChatGPT
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matrix_a = [ [3, 4, -1, 4],
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[-2, 2, 5, 1]
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]
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matrix_b = [ [1, 3, -2],
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[2, 5, 1],
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[-1, 4, -4],
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[2, 3, 6]
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]
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matrix_c = matmul(matrix_a, matrix_b)
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print("Ergebnis C = A * B:")
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for row in matrix_c:
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print(row)
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matrix = [
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[1, 2, 3],
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[4, 5, 6]
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]
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new_matrix = transpose(matrix)
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print("transposed matrix:")
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for row in new_matrix:
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print(row)
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#empty_matrix = []
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#transpose(empty_matrix)
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theta = math.pi / 2
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R = rot_2D(theta)
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print("Rotatiosnmatrix für 90 Grad:")
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print(R)
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p = [[1, 0]]
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rotated = matmul(p, R)
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print("rotated matrix:")
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print(rotated)
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print("Matrix A:")
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print(tabulate(matrix_a))
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