How do I count how many times in a row a value occurs?

16 visualizzazioni (ultimi 30 giorni)
If I have some list, say:
A = [1 2 4 3 1 1 1 1];
How do I calculate and store *how many times in a row* each number occurs?
For example, for the value 1, I would want an output of [1, 4], since it appears one time, then when it appears again in the list it repeats four times.
Any help would be appreciated.

Risposta accettata

Monica Roberts
Monica Roberts il 17 Mag 2022
Probably not the fastest/cleanest but this should work. Assuming that A contains at least one value.
ind = find(A==1);
answer = [];
count = 1;
for i = 1:numel(ind)-1
d = ind(i+1)-ind(i);
if d == 1
count = count+1;
else
answer = [answer,count];
count = 1;
end
end
answer = [answer,count];

Più risposte (1)

Torsten
Torsten il 17 Mag 2022
Modificato: Torsten il 17 Mag 2022
A = [1 2 4 3 1 1 1 1];
Au = unique(A);
count = arrayfun(@(i)numel(find(A==Au(i))),1:numel(Au))
output = [Au;count].'
Your question is unclear since the 1 appears 5 times in the row. If you want the maximum number of subsequent repetitions of a number or something similar, you should again formulate your question properly.

Categorie

Scopri di più su Matrices and Arrays in Help Center e File Exchange

Community Treasure Hunt

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

Start Hunting!

Translated by