Reset value in cumsum matrix when reachin limit, and move the value 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] % B is Input Matrix
A = cumsum (B);
A = [1, 5, 8, 9, 12, 14, 15, 15, 15, 16, 21, 27, 36, 37, 40] % A is output Matrix, which cumulates values in Vector B
C = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] % B is also Output, initial with zero in all vallues.

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 restart the accumulation from 0
C = [0, 5, 0, 0, 7, 0, 0, 0, 0, 0, 9, 6, 9, 0, 0]

[Adam Danz]

A longer example (more than 4 elements) would help communicate the pattern.

For example, what would A and C look like for this vector?

A = cumsum(B); 
A = [1 6 8 9 12 18 20 22 28 30 40 60 61 63 67];

[madhan ravi]

Case closed: https://in.mathworks.com/matlabcentral/answers/461547-an-accumulating-matrix-to-be-reset-when-the-limit-value-is-reached-the-value-being-reset-must-be-mo#answer_374630

Answer 1

[Adam Danz]

First interpretation

I believe the OP wants to integrate over B but not allow the cumulative sum to exceed a threshold of 5. So "A" would be a vector not exceeding 5 while "C" would be a vector of 0s except for the values in "A" that were closest to 5.

% Example data
B = [1, 4, 3, 1, 3, 2, 1, 0, 0, 1, 5, 6, 9, 1, 3]; 
maxVal = 5;   % <-- set the threshold here

% Take the cumulative sum and convert it so that it doesn't exceed the 'maxVal'
A = cumsum(B); 
m = (0:maxVal:max(A))'; 
rm = (max(cumsum((A-m)>0))-1) .* maxVal;  %amount to remove

% Here's your new A vector
Anew = A-rm; 

% Here's your C vector
C = zeros(size(Anew)); 
C(diff(Anew) < 0) = Anew(diff(Anew) < 0); 

Results

Anew =
     1     5     3     4     2     4     5     5     5     1     1     2     1     2     5

C =
     0     5     0     4     0     0     0     0     5     0     0     2     0     0     0

Second interpretation

(as described futher by OP in the comments below).

B = [1, 4, 3, 1, 3, 2, 1, 0, 0, 1, 5, 6, 9, 1, 3];
A = cumsum (B);
C = zeros(size(A)); 
for i = 1:length(A)
    if A(i) >= 5
        C(i) = A(i); 
        A(i:end) = A(i:end)-A(i); 
    end       
end

Results

A =
     1     0     3     4     0     2     3     3     3     4     0     0     0     1     4
C =
     0     5     0     0     7     0     0     0     0     0     9     6     9     0     0

[Adam Danz]

@ Rune Kalhoej If the requirements differ, please provide more details and a better example.

[Rune Kalhoej]

Hello Adam Thank you for your help :)

Its almost what i looked for, i will try to give a better example, whit your methodology

B = [1, 4, 3, 1, 3, 2, 1, 0, 0, 1, 5, 6, 9, 1, 3] % B is Input Matrix
A = cumsum (B);
A = [1, 5, 8, 9, 12, 14, 15, 15, 15, 16, 21, 27, 36, 37, 40] % A is output Matrix, which cumulates values in Vector B
C = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] % B is also Output, initial with zero in all vallues.

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 Vektor A 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]

Hope its well defined ?

[Adam Danz]

See the "Second interpretation" in my answer. It should solve the problem you described above (by the way, you have an error in the last value of your "A" vector; 3 should be 4).

[Rune Kalhoej]

Thank you Adam

Its perfect

[Adam Danz]

Glad I could help.