pick one value from each row in a matrix, to get vector

1 vue (au cours des 30 derniers jours)
Kim
Kim le 8 Juin 2014
I have a 500x8 matrix, lets call this X, and I have a 500x1 vector, lets call it Y, the latter contains numbers between 1 and 8. These numbers indicate the number in each row that I want from the matrix X. So if Y(2,1)=3, then I need X(2,3). So by picking a number in each row of matrix X, I need to get a vector, lets call it Z. I dont know how to get this vector Z, in a quick way (not using a loop). Thank you for your help.

Réponse acceptée

John D'Errico
John D'Errico le 8 Juin 2014
Modifié(e) : John D'Errico le 8 Juin 2014
X(sub2ind(size(X),1:500,Y))
Easily enough done without sub2ind also, but might as well use the existing tool. If you would insist though...
X(1:500 + 500*(Y-1))

Plus de réponses (1)

André Paradis
André Paradis le 8 Juin 2014
for i=1:500
Z=X(i,Y(i))
end
Where Y is a column vector

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!

Translated by