Maximum value of matrix

Hi there,

If we have a complex matrix A, size of (N,M), is there any efficient way to keep the maximum 6 absolute values in A and set others to be zeros? like abs(A(n,m)), keep the top6 biggest one, then set rest to 0.

Really appreciate for anyone leave a comment.

Answer 1

[Kevin Holly]

% Generate random matrix
N = 34;
M = 23;
A = rand(N,M);

% Sort from highest to lowest
values = sort(abs(A(:)), 'descend')

values = 782×1

0.9998 0.9985 0.9980 0.9971 0.9965 0.9962 0.9950 0.9924 0.9914 0.9913

% top 6
values(1:6)

ans = 6×1

0.9998 0.9985 0.9980 0.9971 0.9965 0.9962

values(6)

ans = 0.9962

B = (A>=values(6)).*A

B = 34×23

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.9980 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.9985 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

imshow(B)

[mingcheng nie]

thank you for your answers, really appreciate!

[Kevin Holly]

I would appreciate it if you could accept this answer.

[mingcheng nie]

sure definitely