Python function for creating a square matrix of any size

Question

I need to create a function which can take an unspecified number of parameters (elements for the matrix) and return the corresponding square matrix. I have implemented this using the following approach.

def square_matrix(size, *elements):

    numbers = list(elements)
    if size ** 2 != len(numbers):
        return "Number of elements does not match the size of the matrix"
    else:
        matrix = []
        factor = 0
        for i in range(0, size):
            row = []
            for j in range(factor * size, (factor + 1) * size):
                row.append(numbers[j])
            factor += 1
            matrix.append(row)
            i += 1
        return matrix

print(square_matrix(3, 1, 2, 3, 4, 5, 6, 7, 8, 9))
# Output: [[1, 2, 3], [4, 5, 6], [7, 8, 9]]

Although this method works fine for smaller matrices, it seems somewhat inefficient as it uses nested loops and appears unnecessarily long to me. Is there any better/concise way of implementing the same?

janus235 · Accepted Answer · 2020-09-21 11:12:07Z

3

is it OK to just use NumPy?

import numpy as np

def square_matrix(size, *elements):
    return np.array(elements).reshape(size, size)

answered Sep 21, 2020 at 11:12

janus235

1,5311 gold badge10 silver badges12 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Dhyey Shah Over a year ago

Yes it's fine, I just couldn't figure out a way to implement this with NumPy.

Kazmer Nagy-Betegh · Accepted Answer · 2020-09-21 11:20:02Z

0

For the matrix creation, you could use list comprehension which is more efficient than a for a loop.

You could replace the for loops in the else part of your if statement by the below code.

matrix = [[i for i in elements[j:j+size]] for j in range(0,len(elements),size)]

answered Sep 21, 2020 at 11:20

Kazmer Nagy-Betegh

1

Comments

BioGeek · Accepted Answer · 2020-09-21 11:28:06Z

0

There is no need to give the size as an argument. If the square root of the length of the arguments is a whole number, then you can make a square matrix of the elements.

import numpy as np
from math import sqrt

def square_matrix(*elements):
    size = sqrt(len(elements))
    if size.is_integer():
      return np.array(elements).reshape(int(size), int(size))
    else:
      raise RuntimeError("Number of elements is not sufficient to make a square matrix")


print(square_matrix(1, 2, 3, 4, 5, 6, 7, 8, 9))
# Output:
# array([[1, 2, 3],
#        [4, 5, 6],
#        [7, 8, 9]])

edited Sep 21, 2020 at 11:28

answered Sep 21, 2020 at 11:22

BioGeek

23k23 gold badges90 silver badges156 bronze badges

Collectives™ on Stack Overflow

Python function for creating a square matrix of any size

3 Answers 3

1 Comment

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related