number of elements of each unique values in a matrix

43 visualizzazioni (ultimi 30 giorni)
I can use unique(A) to get an array of each unique value in the matrix A. However, how can I also get an array of the number of elements with each unique value? For instance
B=unique(A) might give:
[1; 4; 6; 8];
and an additional step might give:
[10; 1; 5; 7];
if there were 10 entries of 1, 1 entry of 4, 5 entries of 6, etc.
I know I can easily do this by doing find(A==B(1,1))... etc. but if the array of uniques is long then this should be very inefficient.
Is there a function like unique which returns the number of elements for each unique value without much additional computation??
Thanks

Risposta accettata

Andrei Bobrov
Andrei Bobrov il 15 Ott 2014
B = unique(A);
out = [B,histc(A,B)];
  3 Commenti
Sean de Wolski
Sean de Wolski il 15 Ott 2014
A = [1;1;1;2;3;3];
B = unique(A);
out = [B,histc(A,B)]
out =
1 3
2 1
3 2
First column is value, second is number of occurrences

Accedi per commentare.

Più risposte (0)

Tag

Prodotti

Community Treasure Hunt

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

Start Hunting!

Translated by