Find differences in a set of points without a for loop

5 vues (au cours des 30 derniers jours)
Sonoma Rich
Sonoma Rich le 21 Avr 2015
Commenté : Image Analyst le 19 Mai 2022
I a vector of numbers that I am trying to find the differences between each element in the vector without a for loop. Below is a code example. Is there a more efficient way to execute this code without a for loop?
x = rand(20,1);
diff = zeros(length(x),length(x));
for ix = 1:length(x)
for iy = (ix+1):length(x)
diff(ix,iy) = abs(x(ix) - x(iy));
end
end

Réponses (3)

Image Analyst
Image Analyst le 21 Avr 2015
Modifié(e) : Image Analyst le 21 Avr 2015
diff() is a built in function. Don't use it for a variable name.
For a microscopic length such as 20, don't worry about a for loop. It won't take any time at all, and in fact may take less than calling some fancy function.
  1 commentaire
Image Analyst
Image Analyst le 21 Avr 2015
Richard's "Answer" moved here since it is not an answer to the original question:
Thanks for the help. My actual code has a vector that is much larger. I was just using this as an example.

Connectez-vous pour commenter.


Mehri Mehrnia
Mehri Mehrnia le 19 Mai 2022
I have the question to find all pair-wise difference in a group without loop!
My array in scale of milions!

Bruno Luong
Bruno Luong le 19 Mai 2022
Modifié(e) : Bruno Luong le 19 Mai 2022
x = randi(10,3,1)
x = 3×1
5 4 8
d = abs(x - x.')
d = 3×3
0 1 3 1 0 4 3 4 0

Catégories

En savoir plus sur Loops and Conditional Statements dans Help Center et File Exchange

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by