Basic indexing question Find ismember
3 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Hi World,
I would like to create an index of a matrix based on a vector to resize this array by extracting the indexed rows:
X=(0.5:0.5:17)';
F=(1/52:1/52:30+1/52)';
Q=find(ismember(F,X));
But there are missing values from Q while I can see them in the workspace.
Can you help?
0 commentaires
Réponse acceptée
Stephen23
le 8 Mar 2016
Modifié(e) : Stephen23
le 8 Mar 2016
Basically the numbers that you see are only decimal approximations of the real binary values stored in the computer's memory. With calculations involving decimal fractions these values can differ by a small amount even though they look they same when you look at them in the command window or variable viewer. However they will fail an equality test, and so are not considered to be equal, thus ismember does not match them.
Information on Floating Point Numbers
And some external links on this topic:
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur Matrices and Arrays 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!