how to count a sequence of data arrays with cut off?

i have 5 data in one array. For example, the data array [2.33 2.00 1.60 1.59 1.99]. If the cutoff is 1.50, it means the amount of data is 4 (pay attention to the order of the data). the number 1.99 in the 5th index is not counted.

This is my code

cnr_all=[2.33 2.00 1.60 1.59 1.99];
cut_off=1.50;
N=zeros(size(cnr_all));
for i=1:numel(cnr_all)
    if cnr_all[i] >= cut_off;
        N=N+1;
        break;
    end
end
disp(N)

[Pratyush Swain]

Hi Rahmat,

Can you explain why the 5th index element(1.99) is not included ? Because the first four elements are also greater than the cut off. Can you explain clearly how does this cutoff workflow/method work ?

[VBBV]

% e.g. array
cnr_all=[2.33 2.00 1.60 1.45 1.99];

% cut-off
cut_off=1.50;

N=0;
for i=1:numel(cnr_all)
    if cnr_all(i) >= cut_off;
        N=N+1;
        %break; %comment the break 
    end
end
disp(N)

     4

[rahmat]

dear Pratyush Swain

because I want a trend in the data. For example, there is data from the largest to the smallest (cutoff), but after the smallest data (cutoff) there is data that exceeds the cutoff value. This data is ignored.

For example, A=[5,4,3,2,3] cutoff =2, so the value 3 at index 5 is ignored.

[rahmat]

Dear VBBV

If the cutoff value changes, why does the N value remain 4?

[rahmat]

Dear VBBV

%example array

data_array = [2.33, 2.00, 1.60, 1.59, 1.99];

% Cutoff value

cutoff_value = 2.00;

% Truncates the array to get data above the cut off value

data_above_cutoff = data_array(data_array > cutoff_value);

% Initialize the number of sequences

jumlah_sequence = 0;

% Checking the sequence above the cut off value

for i = 1:length(data_above_cutoff)

if i > 1 && data_above_cutoff(i) ~= data_above_cutoff(i-1) + 1

break; % If there is no sequence, exit the loop

end

jumlah_sequence = jumlah_sequence + 1;

end

disp(['Number of sequences above the cut off value: ', num2str(jumlah_sequence)]);

Answer 1

[Zinea]

Hi rahmat,

I understand from the description that you want the code to stop counting when it encounters a value that is larger than its previous value, while still respecting the cutoff. Here is the code for the same:

cnr_all = [2.33 2.00 1.60 1.59 1.99]; 
cut_off = 1.50; 
N = 0;  

% Start from the second element to compare each element with its predecessor 
for i = 2:numel(cnr_all) 
    % Check if the current element is above the cutoff and less than or equal to the previous one 
    if cnr_all(i) < cut_off || cnr_all(i) > cnr_all(i-1) 
        break; % Exit the loop if the current element is below the cutoff or larger than the previous element 
    end 
    N = N + 1;  
end 

% If the first element meets the initial condition, count it separately 
if cnr_all(1) >= cut_off 
    N = N + 1; 
end 

disp(N) 

The result from the above code is '4' as was mentioned in the question.

Hope it helps!

[rahmat]

Dear Zinea

Thank you very much. Your answer really helped me. If I change the cut off, it will still follow the existing trend.

Answer 2

[Mathieu NOE]

hello

why not simply this ?

% example 1
cnr_all=[2.33 2.00 1.60 1.59 1.99];  
cut_off=1.50;

[~,N] = min(cnr_all - cut_off)

N = 4

% example 2
cnr_all=[2.33 2.00 1.60 1.51 1.53];
cut_off=1.50;

[~,N] = min(cnr_all - cut_off)

N = 4

[rahmat]

dear Mathieu NOE

If the cutoff value changes, why does the N value remain 4?

[rahmat]

Dear Mathieu NOE how about this?

%example array

data_array = [2.33, 2.00, 1.60, 1.59, 1.99];

% Cutoff value

cutoff_value = 2.00;

% Truncates the array to get data above the cut off value

data_above_cutoff = data_array(data_array > cutoff_value);

% Initialize the number of sequences

jumlah_sequence = 0;

% Checking the sequence above the cut off value

for i = 1:length(data_above_cutoff)

if i > 1 && data_above_cutoff(i) ~= data_above_cutoff(i-1) + 1

break; % If there is no sequence, exit the loop

end

jumlah_sequence = jumlah_sequence + 1;

end

disp(['Number of sequences above the cut off value: ', num2str(jumlah_sequence)]);

[Mathieu NOE]

well, I believed I understood yor goal - as you described above

because I want a trend in the data. For example, there is data from the largest to the smallest (cutoff), but after the smallest data (cutoff) there is data that exceeds the cutoff value. This data is ignored.

but what would you expected in this new case ?

%example array

data_array = [2.33, 2.00, 1.60, 1.59, 1.99];

% Cutoff value

cutoff_value = 2.00;

[rahmat]

Dear Mathieu NOE

because each cut off is an input value. And the cut off value can change as an independent variable. The data generated in the array can change. However, it has a trend from largest to smallest (cut off). After the smallest value (cut off) there is a larger value and it is ignored.

[Mathieu NOE]

ok - still I'd like to have from you what then is expected in that case :

%example array

data_array = [2.33, 2.00, 1.60, 1.59, 1.99];

% Cutoff value

cutoff_value = 2.00;