List of neighbors from adjacency matrix
6 visualizzazioni (ultimi 30 giorni)
Mostra commenti meno recenti
Abhishek Varghese
il 14 Feb 2018
Commentato: Steven Lord
il 1 Mar 2018
Hi everyone,
I have an adjacency matrix:
0 1 1 1
1 0 0 1
1 0 0 1
1 1 1 0
I'm trying to create an array that will list the neighbours of each node. Such that I have an output:
[1] 2,3,4
[2] 1,4
[3] 1,4
[4] 1,2,3
An efficient and fast way to compute this would be much appreciated. Cheers.
0 Commenti
Risposta accettata
Matt J
il 14 Feb 2018
Modificato: Matt J
il 14 Feb 2018
yourMatrix=[0 1 1 1
1 0 0 1
1 0 0 1
1 1 1 0];
[i,j]=find(yourMatrix);
result = accumarray(i,j,[size(yourMatrix,1), 1],@(x) {sort(x).'});
>> result{:}
ans =
2 3 4
ans =
1 4
ans =
1 4
ans =
1 2 3
6 Commenti
Nitika Kandhari
il 1 Mar 2018
I tried this:
for i = 1:length(result)
output(i,:)= cellstr(num2str(result{i,1}));
end
and I got 5 X 1 matrix as output:
'1 2'
'3 4 5 6 7'
'8 9 10 11 12 13 14 15 16'
'17 18 19 20 21 22 23 24 29 30 38 39 40 46'
'47 48 49 55 56 61 67 93 94 95 96'
Steven Lord
il 1 Mar 2018
You can't have a matrix in MATLAB where one row has 3 columns and another has 2 columns. You could try padding the shorter rows with missing data using either missing or NaN or padding with 0, but depending on what you want to do with this information it may be simpler just to use the cell array Matt's code creates.
If you tell us what you would do with such a neighbors matrix, we may be able to offer suggestions that will make your later processing easier.
Più risposte (0)
Vedere anche
Categorie
Scopri di più su Matrix Indexing in Help Center e File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!