# Matrix column norm: colnorm colNorm l1norm

### 5.50.5 Matrix column norm: colnorm colNorm l1norm

The column norm of a matrix A is maxj(∑k |aj,k|). (This is also an operator norm; see Section 5.50.6.) The colnorm command finds the column norm of a matrix.
colNorm is a synonym for colnorm, and for matrices l1norm is also a synonym.

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

#### Example.

Input:

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

Output:

6

Indeed: max(1+3,2+4)=6