Filter löschen
Filter löschen

To mirror (i.e, to copy) the upper matrix to the lower half in matrices arranged in 3D

5 Ansichten (letzte 30 Tage)
These two lines mirror (i.e, copy) the upper matrix to the lower half in matrix M, and replace the diagonal elements of the same M with NaN values
M2=triu(M)+triu(M,1)';
%2. To replace the diagonal elements of A with NaN values
M2(eye(size(M2))==1) = nan;
How can I implement them in a 3D array? (e.g., M_3D=374x374x5). The code below does not work.
ns = size(M_3D,3);
M_3D_ = M_3D;
for s = 1:ns
thisM = M_3D(:,:,s);
thisM = triu(M_3D(:,:,s))+triu(M_3D,1)';
M_3D_(:,:,s) = thisM;
M3D_(eye(size(M_3D_(:,:,s)))==1) = nan;
end

Akzeptierte Antwort

Matt J
Matt J am 23 Okt. 2023
Bearbeitet: Matt J am 23 Okt. 2023
M_3D=randi(100, 4,4,3); %fake input
N=size(M_3D,1);
mask=triu(ones(N));
mask(1:N+1:end)=nan;
M_3D=M_3D.*mask;
M_3D=M_3D+pagetranspose(M_3D)
M_3D =
M_3D(:,:,1) = NaN 100 71 68 100 NaN 68 46 71 68 NaN 65 68 46 65 NaN M_3D(:,:,2) = NaN 68 99 23 68 NaN 50 29 99 50 NaN 45 23 29 45 NaN M_3D(:,:,3) = NaN 73 46 4 73 NaN 57 2 46 57 NaN 56 4 2 56 NaN
  2 Kommentare
julian gaviria
julian gaviria am 23 Okt. 2023
It nicely works. Thanks @Matt J
One last question. Do you mind to describe what you did in
mask(1:N+1:end)=nan;
M_3D=M_3D.*mask;
M_3D=M_3D+pagetranspose(M_3D)
Matt J
Matt J am 23 Okt. 2023
It may help to look at the mask,
N=8;
mask=triu(ones(N));
mask(1:N+1:end)=nan
mask = 8×8
NaN 1 1 1 1 1 1 1 0 NaN 1 1 1 1 1 1 0 0 NaN 1 1 1 1 1 0 0 0 NaN 1 1 1 1 0 0 0 0 NaN 1 1 1 0 0 0 0 0 NaN 1 1 0 0 0 0 0 0 NaN 1 0 0 0 0 0 0 0 NaN

Melden Sie sich an, um zu kommentieren.

Weitere Antworten (0)

Kategorien

Mehr zu Operating on Diagonal Matrices finden Sie in Help Center und File Exchange

Produkte


Version

R2023b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by