can someone help me to write the code ?

Hi all

i'm trying to execute my program in matlab in order to ckeck results after a number of iteration under two variables B1 and B2, which are two row vectors with same dimension but i will focus only for the first element of each of them, it means i want to do a number of iteration in order to change the first element of each vector,

so i wrote my code as follow : here B1 should be started from 0 and B2 from 1000.

A_100_iteration = cell(51,1);
Result_100_iteration = cell(51,1);
for ib = 1:51
    B1(1) = (ib-1)*20;
    %code of the first variable
    
    for ib1 = 50:-1 :1
        B2(1) = (ib)*20;
   
     %code of the first variable
        for n = 1:100
            %my program is here 
            
            
            A_100_iteration{ib}=[A_100_iteration{ib},A] ; 
            Result_100_iteration{ib}=[Result_100_iteration{ib},Result] ; %
        end
        B1_100_iteration{ib} = [B1_100_iteration{ib},B1];
        B2_100_iteration{ib1} = [B2_100_iteration{ib1},B2];
    end
end 

the code doesn't work as i want, in each time the dimension of each vector has been changed,knowing that when i did same code for only B1 it works well.

any suggestion please

Answer 1

[Torsten]

A_100_iteration = cell(51,50,1);
Result_100_iteration = cell(51,50,1);
B1_100_iteration = cell(51,50,1);
B2_100_iteration = cell(51,50,1);

for ib = 1:51
    B1(1) = (ib-1)*20;
    %code of the first variable
    
    for ib1 = 1:50
        B2(1) = (51-ib1)*20;
        
        %code of the first variable

        for n = 1:100
            %my program is here 
            
            
            A_100_iteration{ib,ib1}=[A_100_iteration{ib,ib1},A] ; 
            Result_100_iteration{ib,ib1}=[Result_100_iteration{ib,ib1},Result] ; %
        end
        B1_100_iteration{ib,ib1} = [B1_100_iteration{ib,ib1},B1];
        B2_100_iteration{ib,ib1} = [B2_100_iteration{ib,ib1},B2];
    end
end 

[Majid]

@Torsten thank you for your reply, i need just vectors for each A,Result, B1 and B2, with the modification you mentioned i get matrices for each one, when i remove "ib1" as following and i ran B2 also for 51 iterations, i get 51 rows for both B1 and B2, in each row i have the intial vector, but the problem each vector was repeated 51 times , it means instead of seeing the intial dimension of B1 and B2, i see that it was multiplied by 51.

so i'm asking when i put exactly the last two lines in my code in order to eliminate the repetition of the same vector.

A_100_iteration = cell(51,1);
Result_100_iteration = cell(51,1);
B1_100_iteration = cell(51,1);
B2_100_iteration = cell(51,1);
for ib = 1:51
    B1(1) = (ib-1)*20;
    %code of the first variable
    
    for ib1 = 1:51
        B2(1) = (51-ib1)*20;
        
        %code of the first variable
        for n = 1:100
            %my program is here 
            
            
            A_100_iteration{ib}=[A_100_iteration{ib},A] ; 
            Result_100_iteration{ib}=[Result_100_iteration{ib},Result] ; %
        end
        B1_100_iteration{ib} = [B1_100_iteration{ib},B1];
        B2_100_iteration{ib} = [B2_100_iteration{ib},B2];
    end
end 

[Torsten]

B1(1) has range 1:51, B2(1) has range 1:50. For each of these combinations, you run your program. Thus you get 51*50 different results for A_100_iteration. To save these 51*50 results, you will need a matrix of size (51,50).

If you only want to combine B1(1) with B2(1) as value pairs (1/50),(2/49),(3/48), ... , you don't need a second loop. You can just set

for ib = 1:51
    B1(1) = (ib-1)*20;
    %code of the first variable
    B2(1) = (51-ib)*20;
    %code of the first variable
    for n = 1:100
        %my program is here 
        
        A_100_iteration{ib}=[A_100_iteration{ib},A] ; 
        Result_100_iteration{ib}=[Result_100_iteration{ib},Result] ; %
    end
    B1_100_iteration{ib} = [B1_100_iteration{ib},B1];
    B2_100_iteration{ib} = [B2_100_iteration{ib},B2];
end

[Majid]

@Torsten it works now .i really thank you very much for your help and effort usually contribute in order to give help! i appreciated, many thanks.

[Majid]

Hi @Torsten , could you please help me to find the last element in the vector Result _100_iteration , because i have 51 vectors cell in each one the result of 100 iteration(it means 100 elements), but i want to see just the result for last iteration.

thanks in advance

[Torsten]

You mean the last cell, the last element in the last cell or the last element in each cell ?

[Majid]

the last element in each cell

[Torsten]

Still not motivated to take the online MATLAB course for free:

https://de.mathworks.com/learn/tutorials/matlab-onramp.html

?

Only two hours - I think it would help you.

%Generate cell array of row vectors
A_100_iteration = cell(51,1);
for i = 1:51
  A_100_iteration{i} = [2 3 4 5 6 7];
end
%Extract last element from each cell
Array_last_element = zeros(51,1);
for i = 1:51
  Array_last_element(i) = A_100_iteration{i}(end);
end
Array_last_element

Array_last_element = 51×1

7 7 7 7 7 7 7 7 7 7

[Majid]

okay , thank you very much