find a string element in a structure matrix
214 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
assume i have a matrix t =
'abc'
'defg'
'hi'
i want to check if 'abc' is in the matrix t
however this code doesnt seem to work
if (find(t == 'abc') >0)
i get the following error message Undefined function or method 'eq' for input arguments of type 'cell'.
1 commentaire
Réponse acceptée
Jan
le 13 Mar 2012
The shown data cannot be a matrix, because a matrix must have a rectangular shape. I assume you mean a cell string:
C = {'abc', 'defg', 'hi'};
Then:
if any(strcmp(C, 'abc'))
disp('abc found');
end
Plus de réponses (2)
sworland
le 3 Déc 2015
I realize that the answer for this was accepted, but the question did say in a "structure matrix", which I interpreted to mean a structure array. For that the following will find the index of the first occurrence,
index = find(strcmp({structname.field}, 'string')==1)
6 commentaires
Geoff
le 13 Mar 2012
Direct comparison operators (==, etc) don't work with strings.
You need to use strcmp or strcmpi (which ignores case).
Because that function doesn't work on an array, you need to map it:
isabc = cellfun( @(x) strcmp(x,'abc'), t );
This will give you an array of booleans. If you don't care what index the 'abc' occurred at, but just that it exists, you then do this:
if any(isabc)
% etc
end
To obtain the index of the first occurrence, use this:
firstabc = find( isabc, 1 );
-g-
2 commentaires
Jan
le 13 Mar 2012
The == operator does work with strings, try:
a = 'abc', b = '12c', a==b, a=='b';
The only limitation is that both arguments must have the same size or one must be a scalar.
STRCMPI does accept cell strings as inputs such that the CELLFUN approach is not needed.
Voir également
Catégories
En savoir plus sur Characters and Strings 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!