how to count the number of a specific value in a cell array and how to access the index of each value

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Dongyan Zhu
Dongyan Zhu on 18 Nov 2020
Edited: Superficial on 18 Nov 2020
Dear all,
i am now working with a cell array with fixed length:
VtStatus = {1,0,0,0,0,0};
and I also created 6 checkboxes to manage this cell array, e.g.: If I want to mark the checkboxes instead of the 3rd and the 5th, then this array goes like this:
VtStatus = {1,1,0,1,0,1};
Here comes the question: I want to know how many ''1'' are in this array and also the position of these ''1'' (e.g: I want to get the index of ''active checkboxes'' as a string '1-2-4-6' ). Which functions should I use?
Many thx!

Accepted Answer

Ameer Hamza
Ameer Hamza on 18 Nov 2020
Edited: Ameer Hamza on 18 Nov 2020
If possible, use numeric array for this type of data. They will be much more efficient and easy to deal with. For cell array, you can try something like this
VtStatus = {1,1,0,1,0,1};
loccation = find([VtStatus{:}]);
num = numel(loccation);
active_checkboxes = strjoin(string(loccation), '-');
Result
>> loccation
loccation =
1 2 4 6
>> num
num =
4
>> active_checkboxes
active_checkboxes =
"1-2-4-6"

More Answers (2)

João Mendes
João Mendes on 18 Nov 2020
To know the positions of the active checkboxes you can write:
active= find([a{:}]==1)
To know how many are active, i.e., how many '1's' exist, youc an write:
number=size(active,2)
It helps?

Superficial
Superficial on 18 Nov 2020
Edited: Superficial on 18 Nov 2020
Convert from a cell to a vector and it's easy.
VtStatus = {1,1,0,1,0,1};
vec=[VtStatus{:}] % Convert to a vector
inds=find(vec==1) % The index of each cell equal to one
str=num2str(inds) % You can convert inds to a string if you like
count = length(inds) % The number of cells equal to one
Gives the answers:
vec =
1 1 0 1 0 1
inds =
1 2 4 6
str =
'1 2 4 6'
count =
4

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