Matrix Rank via Row Reduction

Problem

Compute the rank of a matrix A: the number of nonzero pivots after Gaussian elimination.

Use a tolerance of 1e-9 when deciding whether a pivot is nonzero.

Hint

Eliminate entries below each pivot, then count the pivots.

case 1

in: [[[1,2],[3,4]]]

expected: 2

case 2

in: [[[1,2],[2,4]]]

expected: 1

case 3

in: [[[1,2,3],[4,5,6],[7,8,9]]]

expected: 2

case 4

in: [[[0,0],[0,0]]]

expected: 0

Starter codePython

def matrix_rank(A):
    # Your code here
    pass

4 test cases · run your code against them in the editor