How to create a vector by iteration

Hello everyone,

I am working on a program that creates a vector from tthree other vector by iterations with the following formula :

I would like to create the vector F whcih represent a baseline calculated by iteration from P1, P2 and G which also are vectors with the same number of elements. Here are the steps I have to follow : 1. Define the vectors, G(t), Pl(t) and P2(t), so that all have an equal number of elements. 2. Set F(t) equal to Pl(t) and evaluate the right-hand side of Eq. 3. 3. Set the evaluated F(t) equal to the input F(t) and perform step 2 again. Repeat this procedure until F(t) does not change further when the output of the preceding iteration is put equal to the input of the next. I am struggling at step 3. I don't know how to create the loop. Here is my code for the moment : % Iterative baseline using Bandara method clear all close all

dataset = xlsread('ramp.xlsx','A15000:B130000');

% Variables x = dataset(:,1); y = dataset (:,2);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % Time vector t = 27 : 1 : 218; % Vectors P1 and P2 P1 = 0.000148 + -0.000182 * t.^1; P2 = 0.027040 + -0.000329 * t.^1; % Vector G G = interp1(x,y,t); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%% Definition of F %%%%% F0 = P1; Fnew = zeros(1,length(t)); it = 1; % Iteration number fun = @(t)G-F0;

while true for ii = 1 : length(t) Fnew(ii) = (integral(fun,t(1),t(ii),'ArrayValued',true) / integral(fun,t(1),t(end),'ArrayValued',true)) * (P2(ii) - P1(ii)) + P1(ii); if Fnew(ii) - F0(ii) < 0.1 break end end F0 = Fnew; it = it+1; end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

hold on % plot(x,y,'r-','linewidth',2); plot(t,P1,'linewidth',2); plot(t,P2,'linewidth',2); plot(t,G,'linewidth',2); plot(t,Fnew,'linewidth',2); Does anyone have an idea of what is wrong with my code ? You will find enclosed the excel file related to the code. Thanks in advance for your help.

Answer 1

[Jan]

The break stops the for loop, but there is no exit from the outer while loop:

while true
    for ii = 1 : length(t)
      Fnew(ii) = (integral(fun,t(1),t(ii),'ArrayValued',true) / integral(fun,t(1),t(end),'ArrayValued',true)) * (P2(ii) - P1(ii)) + P1(ii);
      if Fnew(ii) - F0(ii) < 0.1
          break
      end
    end
    F0 = Fnew;
    it = it+1;
end

Maybe you mean:

proceed = true;
while proceed
    for ii = 1 : length(t)
      Fnew(ii) = (integral(fun,t(1),t(ii),'ArrayValued',true) / ...
                  integral(fun,t(1),t(end),'ArrayValued',true)) * ...
                  (P2(ii) - P1(ii)) + P1(ii);
      if Fnew(ii) - F0(ii) < 0.1
          proceed = false;   % Will stop the WHILE loop
          break              % exits the FOR loop
      end
    end
    F0 = Fnew;
    it = it+1;
end