L1 and l2 norm

i'm trying to find the code not the function to implement L1 and L2 norm.

I'm trying to compute the L1 and L2 norm of pixels in a image to see the difference between them.

Answer 1

[Johnathan Schaff]

Reference https://www.mathworks.com/help/matlab/ref/norm.html#bt0y64b-5

%Matrix Norm for Matrix A
%L1 Norm
l1 = max(sum(abs(A)));
matL1 = norm(A,1);

%L2 Norm
l2 = max(svd(A));
matL2 = norm(A,2);

%Comparison
fprintf('L1 Norm | %g\nMATLAB L1 Norm | %g\n',l1,matL1);
fprintf('L2 Norm | %g\nMATLAB L2 Norm | %g\n',l2,matL2);

%Vector Norm for Vector B
%L1 Norm
l1 = (sum(abs(B)));
matL1 = norm(B,1);

%L2 Norm
l2 = sqrt(sum(abs(B).^2));
matL2 = norm(B,2);

%Comparison
fprintf('\nL1 Norm | %g\nMATLAB L1 Norm | %g\n',l1,matL1);
fprintf('L2 Norm | %g\nMATLAB L2 Norm | %g\n',l2,matL2);

Answer 2

[JMW]

To get column norms:

L1=vecnorm(A,1)

L2=vecnorm(A,2)