Code to solve determinant using Python without using scipy.linalg.det

Question

Description(this is a hwk question):

I am not sure where to start here. I plan to use Laplace's Expansion but I am not sure how to implement it for nxn matrices. Any help would be appreciated.

Note: I already have a function to generate random matrices for a nxn matrix. Also the timing the calculation isn't a problem. The only thing I have an issue is how to calculate the determinant.

Had to delete the question description b/c of my class policy.

Answer 1

Ok, here's a hint.

1. write a function to calculate the minor matrices. (hint, use slices)
2. write a function to calculate the cofactors (this should call the first function, and the determinate function)
3. the determinate function calls the function in step two and adds the results together. (hint: use sum)

viola, you have a determinant.

Also, don't forget that because of the way we write lists in python, the indices get reversed. That is if

M = [[1, 2, 3],
     [4, 5, 6],
     [7, 8, 9]]

then m_0,1 is 2 and not 4 as it would be in normal notation. you can think of it as a transpose or use zip