All Questions
163 questions
3
votes
3
answers
136
views
Determinant of matrix Python
This is an addition of my previous question Python matrix class. I've added a determinant function using Laplace expansion to my Matrix class. What I am looking for specifically is how 3x3 matrices ...
- 10.7k
8
votes
5
answers
1k
views
Python matrix class
To prepare for my studies in linear algebra, I've decided to write a simple matrix class. This is the initial program, with functions to find the determinant and decomposition(s) to follow. I wanted ...
- 10.7k
15
votes
4
answers
2k
views
Create a snail matrix
Statement:
Create a script that, given an integer \$n\$, create a square matrix of dimensions \$n \times n\$ with the numbers from \$1\$ to \$n^2\$, arranged in a snail pattern.
Example:
...
- 633
4
votes
2
answers
203
views
Matrix Factorisation class packaging methods for factorisation of explicit & implicit data matrices using Gradient Descent, SGD and ALS
Attached below, and also as this GitHub gist, is code for a Python class I wrote as part of a personal learning/portfolio project on collaborative-filtering recommender systems via matrix ...
- 43
0
votes
1
answer
325
views
Approximation of the multiplicative matrix inverse (linalg.inv ())
I am trying to compute the multiplicative inverse of a large matrix (~ >40,000x40,000). This can be done with e.g. numpy.linalg.inv or ...
- 103
2
votes
1
answer
143
views
Returning all divisors of a number as a matrix with N X 2 dimensions
I have developed a class structure with methods to return a matrix from a single input array. The objective is to insert the middle value of the array so 2n remains ...
- 23
1
vote
2
answers
85
views
Validator for 0/1 entries in a matrix
I build a function(A kind of puzzle) that counts from a matrix the number of valid count (Explanation below).
The matrix is made up of 0,1.
Input-
a matrix- list of lists
row number
column number
...
- 13
3
votes
0
answers
1k
views
Return a 2D matrix from a C++ function in Python: ctypes versus pybind11
I found two ways in which I can use a custom C++ function (returning a 2D matrix) in Python. One approach that uses the Python module ctypes and another that uses the Python module pybind11.
Approach ...
- 331
5
votes
2
answers
392
views
Rotating a matrix clockwise by one element without any libraries (Python 3.9)
The question is as follows:
Rotate an NxN matrix clockwise by one element and display the new matrix.
For example, if
...
- 73
3
votes
1
answer
144
views
Python: Create submatrices from long/narrow table and save in HDF5
Hello dear StackExchange Community,
I have written a small program which is doing the following. In short:
it reads in a table in narrow format
creates submatrices from it
saves it in HDF5 format
...
- 85
1
vote
1
answer
91
views
Vectorized code to find the position and length of runs of 1s in a bit matrix
I'm trying to write something like an adjusted run-length encoding for row-wise bit matrices. Specifically I want to "collapse" runs of 1s into the number of 1s in that run while maintaining ...
- 926
3
votes
1
answer
412
views
Find number of ways to traverse matrix of 0's and 1's
I solved a Daily Coding Challenge, but i suspect my code could be optimised. The challenge is the following:
You are given an N by M matrix of 0s and 1s. Starting from the top left corner, how many ...
- 33
1
vote
1
answer
3k
views
Lo Shu Magic Square (Python)
I wrote a python program to find if a matrix is a magic square or not. It works, but I can't help feeling like I may have overcomplicated the solution. I have seen other implementations that were a ...
- 325
2
votes
2
answers
809
views
Finding distance between vectors of matrices
So here is the problem:
Given 2D numpy arrays 'a' and 'b' of sizes n×m and k×m
respectively and one natural number 'p'. You need to find the
distance(Euclidean) of the rows of the matrices 'a' and ...
- 315
2
votes
1
answer
821
views
Finding the Euclidean distance between the vectors of matrix a, and vector b
Here is the problem,
Given a 2D numpy array 'a' of sizes n×m and a 1D numpy array 'b' of
size m. You need to find the distance(Euclidean) of the 'b' vector
from the rows of the 'a' matrix. Fill the ...
- 315