### 15.4.5 Matrix column norm

The column norm of a matrix A is maxj(∑k |aj,k|). (This is also an operator norm; see Section 15.4.6.) The colnorm or colNorm command finds the column norm of a matrix. For matrices, l1norm is also a synonym.

- colnorm takes A, a matrix
- colnorm(A) returns the column norm of A.

#### Example

colnorm([[1,2],[3,-4]])

6 |  |  |  |  |  |  |  |  |  |

Indeed, max{1+3,2+4}=6.