How to get all values existing in arrays/matrices?

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Arif Widianto
Arif Widianto 2020-3-24
编辑： Andrei Bobrov 2020-3-24
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.

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采纳的回答

Andrei Bobrov
Andrei Bobrov 2020-3-24
编辑：Andrei Bobrov 2020-3-24
[a,~,c] = unique(reshape(myArray',[],1),'stable');
out = [a, accumarray(c,1)];
or
out = varfun(@(x)x,array2table(myArray(:)),'GroupingVariables',1);
  2 个评论
Arif Widianto
Arif Widianto 2020-3-24
编辑：Arif Widianto 2020-3-24
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 2020-3-24
编辑：Andrei Bobrov 2020-3-24
Yes or:
[a,~,c] = unique(myArray);
out = [a, accumarray(c,1)];

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更多回答（2 个）

KSSV
KSSV 2020-3-24
编辑：KSSV 2020-3-24
Read about unique
a = myArray(:) ;
[cnt_unique, unique_a] = hist(a,unique(a)) ;
Walter Roberson
Walter Roberson 2020-3-24
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.

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