How to use if command?
5 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Say I have a table X = (columnA, columnB, columnC) What is wrong with the following command? The result is always columnB = columnA no matter what condition and which line. There are numbers in columnA smaller than 30 or larger than 90 just so you know. Thank you in advance!!
for i = 1:numel(columnA)
if 30 < columnA(i) < 90
columnB(i) = columnA(i);
else
columnB(i) = columnC(i);
end
end
end
1 commentaire
Stephen23
le 21 Mai 2018
The syntax you use does not do what you think it does. You will need to use
A<X && X<B
The syntax that you used is equivalent to this:
(A<X)<B
You can learn why by reading the MATLAB documentation:
Réponse acceptée
Walter Roberson
le 21 Mai 2018
30 < columnA(i) < 90 means the same as ((30 < columnA(i)) < 90) . The first part results in 0 (false) or 1 (true), and that 0 or 1 is then compared to 90 and since both are < 90, the result of the test is always true.
MATLAB does not have any range tests of the form A < x < B , with the exception that such ranges are sometimes recognized in some MATLAB versions but only in calls to piecewise()
2 commentaires
Walter Roberson
le 21 Mai 2018
mask = 30 < X.ColumnA & X.ColumnA < 90;
X.ColumnB(mask) = X.ColumnA(mask);
X.ColumnB(~mask) = X.ColumnC(~mask);
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur Loops and Conditional Statements 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!