How to exclude rows on the basis of specific entries?
36 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
I have 260 rows and 16 columns with entries belong to {1,2,3,4}, I want to exclude those rows in which first four entries of each row is 4 , or in general how can I exclude rows on the basis of entries?
0 commentaires
Réponse acceptée
Guillaume
le 6 Fév 2018
It's not clear what you mean by repeat.
If you mean you want to delete rows whose first four columns contain more than one 4:
A = [4 4 1 2; 4 4 4 4;1 4 2 4;4 2 3 2]
todelete = sum(A(:, 1:4) == 4, 2) > 1;
A(todelete, :) = []
If you mean you want to delete rows whose first four columns contain two more more consecutive 4, then it's a lot more complicated. One possible way
A = [4 4 1 2; 4 4 4 4;1 4 2 4;4 2 3 2]
todelete = cellfun(@(row) ~isempty(strfind(row, [1 1])), num2cell(A(:, 1:4) == 4, 2));
A(todelete, :) = []
9 commentaires
Plus de réponses (1)
Jos (10584)
le 6 Fév 2018
Here is a flexible example:
% data
X = [4 4] ; % rows starting with this should be discarded
A = [1 4 1 4 ; 4 4 2 2 ; 4 2 4 0 ; 4 4 4 4 ; 2 4 4 2] ; % rows 2 and 4 should be discarded
% engine
tf = ismember(A(:,1:numel(X)), X, 'rows')
A(tf) = [] ; % remove
0 commentaires
Voir également
Catégories
En savoir plus sur Creating and Concatenating Matrices dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!