Python – 3D Matrix to Coordinate List

Python – 3D Matrix to Coordinate List

Converting a 3D matrix to a coordinate list can be useful in various applications such as sparse matrix representation, computer graphics, and computational physics. A 3D matrix can be visualized as a cube, with each element having three indices (x, y, z) representing its position. A coordinate list, on the other hand, is a list of tuples where each tuple consists of the (x, y, z) coordinates of the non-zero elements and their values.

Let's break down the process:

  • Setting up a 3D Matrix: A 3D matrix in Python can be represented using nested lists. Here's a simple example:
matrix_3d = [ [[0, 0, 2], [0, 5, 0], [7, 0, 0]], [[0, 8, 0], [0, 0, 0], [0, 0, 0]], [[3, 0, 0], [0, 4, 0], [0, 0, 6]] ]

This matrix has dimensions 3x3x3.

  • Converting 3D Matrix to Coordinate List: Loop through each element of the 3D matrix and if the element is non-zero, add its coordinates and value to the list.
def matrix_to_coord_list(matrix_3d): coord_list = [] for x in range(len(matrix_3d)): for y in range(len(matrix_3d[x])): for z in range(len(matrix_3d[x][y])): if matrix_3d[x][y][z] != 0: coord_list.append((x, y, z, matrix_3d[x][y][z])) return coord_list coord_list = matrix_to_coord_list(matrix_3d) print(coord_list)

Output:

[(0, 0, 2, 2), (0, 1, 1, 5), (0, 2, 0, 7), (1, 0, 1, 8), (2, 0, 0, 3), (2, 1, 1, 4), (2, 2, 2, 6)]

This list gives us the (x, y, z) coordinates of non-zero elements and their respective values.

  • Optional: Converting Back to a 3D Matrix: In case you'd want to revert your coordinate list back to a matrix:
def coord_list_to_matrix(coord_list, dims): matrix_3d = [[[0 for _ in range(dims[2])] for _ in range(dims[1])] for _ in range(dims[0])] for coord in coord_list: x, y, z, value = coord matrix_3d[x][y][z] = value return matrix_3d dims = (3, 3, 3) # Given dimensions reconstructed_matrix = coord_list_to_matrix(coord_list, dims) print(reconstructed_matrix)

Output would be the original 3D matrix.

You can use these functions as a starting point and further enhance or optimize them based on your specific needs.

More Tags

class-attributes batch-rename pom.xml cardlayout django-testing jq cordova-cli clob azure-cosmosdb-sqlapi hql

More Programming Guides

Other Guides

More Programming Examples