How do I set maximum summing value

Hello. I really need help

I have variable P_bat type 2880x1. Values are from -100 to +100. Then these values addition(sum) with for loop and I get this graph (bat_sum)

Up to here everything is working well. So i want define maximum value of bat_sum.

When the value is equal to max_value , addition must stopped but subtraction must work (specifically addition negative values must work).

For easier to understand, imagine how "battery work"

This is my code

clc; close all; clear all
P_bat=importdata('P_bat.mat') 
max_value=10000 
for j=1:size(P_bat(1:(end),1));
bat_sum(j)=(sum(P_bat(1:j))); 
end
figure (1)
hold on
grid on
title ('bat_sum')
plot(bat_sum)

OneDrive link https://onedrive.live.com/redir?resid=DD620BBD5358C89F!71076&authkey=!AKU8HYU0jT5iTaY&ithint=folder%2cmat

if anyone has any ideas? THANKS!

Answer 1

[Azzi Abdelmalek]

max_value=10000
bat_sum(1)=P_bat(1)
for jj=2:numel(P_bat)
   bat_sum(jj)=bat_sum(jj-1)+P_bat(jj);
   if bat_sum(jj)>1000
       bat_sum(jj)=bat_sum(jj)-P_bat(jj);
   end
end
plot(bat_sum)

[Walter Roberson]

The "if" should result in

bat_sum(jj) = max_value;

The value that pushes it over max_value should not be fully removed -- e.g., 990 + 15 should not go to 1005 then back to 990, it should saturate at 1000

[jlive]

Almost right. But the value must be calculated up to a maximum like as in the #Image Analyst code .Thank you very much for your reply. I see that good people still exist !

Answer 2

[Image Analyst]

Put this line in at the bottom of the for loop

if bat_sum(j) > max_value
    break; % Exit the for loop
end

If you want it to saturate to the max value after it attains that value, then preallocate bat_sum before the for loop:

numElements = size(P_bat(1:(end),1));
bat_sum = zeros(1, numElements);

and then have the if block do this:

if bat_sum(j) > max_value
    bat_sum(j:end) = max_value; % Same value until the end.
    break; % Exit the for loop
end

[Walter Roberson]

This would not reduce the sum when negative values were encountered.

[Image Analyst]

When he said "When the value is equal to max_value , addition must stopped" I thought that meant bail out of the loop so you're not adding anything - not adding positive numbers and not adding negative numbers. Maybe still wants to add in negative numbers. It's kind of ambiguous. Maybe this is what is wanted:

max_value = 10000
bat_sum(1) = P_bat(1)
hitTheMax = false;
for k = 2 : numel(P_bat)
  if hitTheMax
    % We've hit the target value.
    % Only add in a value if it's negative.
    if P_bat(k) < 0
      % Negative, so it's okay to add in now.
      nextValue = bat_sum(k-1) + P_bat(k);
    else
      % Positive value, so don't add it in,
      % just maintain the same previous value.
      nextValue = bat_sum(k-1);
    end
  else
    % Not his the max yet, so either positive
    % or neative P_bat values are acceptable.
    nextValue = bat_sum(k-1) + P_bat(k);
  end
  % Once it's past max_value,
  % only add in negative values, not positive ones
  % so the signal only gets smaller monotonically.
  if nextValue > max_value
    % Clip to max_value
    bat_sum(k) = max_Value;
    % Flag that we will only add in negative numbers from now on.
    hitTheMax = 0;
  else
    % We would be less than the max
    bat_sum(k) = nextValue;
  end
end
plot(bat_sum)

[Walter Roberson]

"but subtraction must work (specifically addition negative values must work)."

With his reference to "battery" I think the model should be that the accumulator saturates at the given limit, that it can never be pushed above that point but that negative values can draw it down at which point positive values can push it back up. The same thing as the way MATLAB int8 or int16 work.

>> cumsum(int8([120,15,2,-5]))
120  127  127  122

[Image Analyst]

I wasn't sure what to make of the battery reference. I thought of that - like positive values would bring it up like a battery was recharging or something. But I don't have the Mind Reading Toolbox like you :-) so I just went verbatim by what he said - that once it hits the max, it quits adding in positive values anymore ("addition must stopped"), though I could be wrong.

[jlive]

I apologize for my unclear question

Yes, it is correct!

Thanks guys, you are amazing!. I'm really happy that you helped me!