# Matrix norm Calculator

## Calculates the L1 norm, the Euclidean (L2) norm and the Maximum(L infinity) norm of a matrix.

 matrix A {aij} 6digit10digit14digit18digit22digit26digit30digit34digit38digit42digit46digit50digit Matrix norm
Matrix norm
 [1-5] /5 Disp-Num5103050100200
[1]  2019/12/09 13:44   Male / 20 years old level / High-school/ University/ Grad student / Useful /
Purpose of use
To double-check my L2 norm calculations.
Bug report
Incoorect L2 norm computed for the following matrix:
2 -1 0 0
-1 2 -1 0
0 -1 2 -1
0 0 -1 2

Maximum eigenvalue for this symmetric matrix is 3.61803398875
Not 2.61803398875, as calculated here.
from Keisan
We've fixed the bug.
[2]  2019/10/15 11:31   Male / 20 years old level / High-school/ University/ Grad student / Very /
Purpose of use
Learn L2 norm
[3]  2019/10/02 07:09   Male / Under 20 years old / High-school/ University/ Grad student / Very /
Purpose of use
homework check
[4]  2019/08/18 15:44   Female / 40 years old level / An office worker / A public employee / A little /
Purpose of use
learning how to norm matrix for my work.
The examples helps
[5]  2018/01/20 05:51   Male / 50 years old level / An engineer / Useful /
Bug report
The text definition of the L2 norm is incorrect. The calculated result is correct though.

Is says it''s the maximum eigenvalue of A, that is lambda_max(A).
Instead it should say that it''s the largest spectral radius, that is sigma_max(A).
Equivalently that''s the largest eigenvalue of A^T.A (or A^* A for complex matrices).
See e.g. https://en.wikipedia.org/wiki/Matrix_norm
from Keisan
We have fixed it.

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