Remove some elements from a matrix but conserve the same struct
7 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
i have the matrix
x=[0 -1 0 5 10 5 0 0;
0 0 5 10 20 10 5 0;
1 -1 0 5 10 5 2 0;
0 2 1 0 5 2 1 0;
0 0 0 -10 0 0 0 0;]
i would like to "disappear" the values between -1 and 5 and keep the matrix with same struct but only the wanted values. the new matrix going to be something like this:
x=
[ 10 ;
10 20 10 ;
10 ;
;
-10 ;]
0 Kommentare
Akzeptierte Antwort
Matt Fig
am 29 Mär. 2011
You will have to use cell arrays if you want to preserve the shape:
X = num2cell(x); % A cell array with the same shape as x.
X(x<=5 & x>=-1) = {[]}
Is there a practical reason for doing this? It seems like a large waste of memory to me. If you need to keep the indices viewable, you also could do this:
X = x;
X(x<=5 & x>=-1) = 0;
X = sparse(X)
Weitere Antworten (2)
Sean de Wolski
am 29 Mär. 2011
Rafael, then set everything in the range you described to NaN, and mesh will pretend they're not there.
X(X>=-1&X<=5) = nan;
mesh(X);
You can reduce the size of the matrix first by zeroing out any rows/columns that contain no "peaks". Use the ANY function and the dimensional option to do this.
3 Kommentare
Matt Fig
am 29 Mär. 2011
+1 Sean!
@ Rafael I hope next time you will include the "why" when asking about the "how!" ;-)
Siehe auch
Kategorien
Mehr zu Get Started with MATLAB finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!