Matrix 1-Norm (Max Column Sum)

Problem

Compute the induced matrix 1-norm: the maximum over columns of the sum of absolute entries in that column.

||A||_1 = max_j sum_i |A[i][j]|.

Hint

Sum down each column, then take the largest column total.

case 1

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

expected: 6

case 2

in: [[[1,2,3],[4,5,6]]]

expected: 9

case 3

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

expected: 0

case 4

in: [[[-1.5,2]]]

expected: 2

Starter codePython

def matrix_1_norm(A):
    # Your code here
    pass

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