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

treshold

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]

Best Answer

  • 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