An accumulating matrix to be reset when the limit value is reached, the value being reset must be moved to another matrix

Hello

can someone please help me with this challenge.

matrix

B = [1, 4, 3, 1, 3, 2, 1, 0, 0, 1, 5, 6, 9, 1, 3]
A = cumsum (B);
A = [1, 5, 8, 9, 12, 14, 15, 15, 15, 16, 21, 27, 36, 37, 40]

Then i want A and C to act like this

A = [1, 0, 3, 4, 0, 2, 3, 3, 3, 4, 0, 0, 0, 1, 3] % Every time it exceds 5, the value has to be moved to C, and reset to 0
C = [0, 5, 0, 0, 7, 0, 0, 0, 0, 0, 9, 6, 9, 0, 0]

[Rik]

I suspect you can't solve this without a loop. What have you tried so far yourself?

[Rune Kalhoej]

primary loops, like this

clc

B = [5,3,4,7,8,6,3,2,1,0,3,2,7,8,3,4,2];
A = cumsum(B); %Dette er den matrice du vil sortere alt over 5

C = zeros(length(A),1); %Alle værdier over 5 fra Matrix matricen, bliver lagt over i denne, resten er 0.

for i = 1:length(A) 
    if A(i)>=5
        C(i) = A(i);
        A(i) = 0;     % den skal samtidig nulstilles , virker ikke :S
    else 
        C(i) = 0;
    end

end

table(A',C)

[Adam Danz]

Duplicate

https://www.mathworks.com/matlabcentral/answers/461364-reset-value-in-cumsum-matrix-when-reachin-limit-and-move-the-value-to-another-matrix

Answer 1

[Rik]

This should do the trick. Note that you should use numel to count the number of elements, not length, which is just doing max(size(A)). The difference is usually nothing, but it will trip you up at some point.

B = [1, 4, 3, 1, 3, 2, 1, 0, 0, 1, 5, 6, 9, 1, 3];
A = cumsum (B);
C = zeros(size(A));
idx=find(A>=5);
while ~isempty(idx)
    idx=idx(1);
    C(idx)=A(idx);
    A(idx:end)=A(idx:end)-A(idx);
    
    idx=find(A>=5);
end
FormatSpec=[repmat('%d, ',1,numel(A)) '\n'];FormatSpec(end-3)='';

clc
fprintf(FormatSpec,A)
fprintf(FormatSpec,C)

Alternatively (which might be faster in some cases):

B = [1, 4, 3, 1, 3, 2, 1, 0, 0, 1, 5, 6, 9, 1, 3];
A = cumsum (B);
C = zeros(size(A));
idx=find(A>=5);
while ~isempty(idx)
    idx=idx(1);
    C(idx)=A(idx);
    A=A-A(idx);
    
    idx=find(A>=5);
end
A=cumsum(B)-cumsum(C);%restore real A

[Rune Kalhoej]

Thank you Rik - "Not all heroes wear capes" ;)

Its exactly what i was looking for...

[Rik]

You're welcome, glad to be of help.