How to get all values existing in arrays/matrices?

67 views (last 30 days)
Hello,
Let say I have a 3-by-2 array with random integer values. For example,
myArray = [98 56; 58 52; 100 56];
What I want to do is, I want to get all value in the array and its frequency and save it to another array like this,
listValue = [98 1; 56 2; 58 1; 52 1; 100 1];
Is there any function or a way to do it?
Thank you in advance.

Accepted Answer

Andrei Bobrov
Andrei Bobrov on 24 Mar 2020
Edited: Andrei Bobrov on 24 Mar 2020
[a,~,c] = unique(reshape(myArray',[],1),'stable');
out = [a, accumarray(c,1)];
or
out = varfun(@(x)x,array2table(myArray(:)),'GroupingVariables',1);
  2 Comments
Arif Widianto
Arif Widianto on 24 Mar 2020
Edited: Arif Widianto on 24 Mar 2020
The first one works for my case. So, if I want it sorted, the only thing I need to do is changing 'stable' to 'sorted' right?
Andrei Bobrov
Andrei Bobrov on 24 Mar 2020
Edited: Andrei Bobrov on 24 Mar 2020
Yes or:
[a,~,c] = unique(myArray);
out = [a, accumarray(c,1)];

Sign in to comment.

More Answers (2)

KSSV
KSSV on 24 Mar 2020
Edited: KSSV on 24 Mar 2020
Read about unique
a = myArray(:) ;
[cnt_unique, unique_a] = hist(a,unique(a)) ;

Walter Roberson
Walter Roberson on 24 Mar 2020
See unique() and accumarray. Or unique and histc or histcounts (but be careful about the last value in histcounts). Or use a loop. Or use sparse(). Lots of ways.

Categories

Find more on Creating and Concatenating Matrices in Help Center and File Exchange

Tags

Community Treasure Hunt

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

Start Hunting!