corr2 return 1 for different value
2 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
why when i use corr2 for different value in matlab return result=1 although the tow matrix not similar like this:-
aa
aa =
137.5093 1.9847
>> bb
bb =
141.2252 3.3757
>> corr2(aa,bb)
ans =
1
0 commentaires
Réponses (1)
Ameer Hamza
le 20 Sep 2020
If you use only 2D vectors with corr2(), it is always possible to draw a line connecting two points, so the correction coefficient is always 1 or -1. You can verify this by simplifying the formula: https://www.mathworks.com/help/releases/R2020a/images/ref/corr2.html#f1-227958 for the case when x and y are 2D vectors.
8 commentaires
Walter Roberson
le 21 Sep 2020
If you try something like
[H,p] = ttest2(aa,bb)
you will get a p > 0.9 -- that is, if you treat the numbers as being a random distribution, there is more than a 90% chance that they come from the same random distribution.
The large value of the second feature dilutes the variation in the other features. If you take the correlation with the second feature removed, you will get a notably lower score. Perhaps you should rescale the second feature.
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!