How to fix my for loop to continue to the next value in the list when condition is false?

Hi,

Could anyone help me with how I could fix my code so it continues to check the next value in the list (Besparingslistan) if the condition in the IF-statement is false?

Also, right now I get the error "Index exceeds the number of array elements (13)." How can I fix it?

(The "Besparingslistan" is a list with the size 169x3 built up with different combinations of 13 different customers in the first two columns and a savingsvalue in the third column. While Kund_i_tur and Turkonfig are column vectors with the customers, aka (1:1:13). )

f = size(Besparingslistan,1);
a = size(Besparingslistan,2);
for forstatur = 1:f
    for andratur = 1:a
        if Kund_i_tur(f)~= Kund_i_tur(a)
           Turkonfig = {f a};
        end
    end
end   

[madhan ravi]

Upload Besparingslistan as .mat file.

[Amanda S]

I dont have matlab available at the moment but I hope an Excel file still works so you see the list at least

[Image Analyst]

What does this show in the command window:

whos Besparingslistan
whos Kund_i_tur

It seems like either (the poorly named) f or a is larger than the length of Kund_i_tur.

[Amanda S]

It says:

>> whos Besparingslistan

whos Kund_i_tur

Name Size Bytes Class Attributes

Besparingslistan 169x3 4056 double

Name Size Bytes Class Attributes

Kund_i_tur 13x1 104 double

And i understand that the varibles are different sizes but I dont know how to do it any other way since I want to loop through Besparingslistan with "forstakund" as row i column 1 and "andrakund" as row i column 2. forstakund and andrakund are supposed to change value as the loop iterations goes forward.

Kund_i_tur is supposed to represent a vector that eventually will be updated and show which routes that the customers 1-13 is part of (the whole code is based on the Clarke & Wright savings algoritm), therefore I dont know how to do it another way...

Answer 1

[Arjun]

Hi @Amanda,

I see that you have a piece of code and you are facing an error “Index exceeds the number of array elements (13)” and want to fix it.

The issue is that since you mentioned that “kund_i_tur” is a column vector having 13 rows, but you are trying to index it using “f” which can have values ranging from 1 to 169 and hence this error. To fix that, a simple if statement to check the range of “f” is required. Apart from this the logic to fetch “forstatur” and “andratur” as first and second column of the row is not correct. The correct logic to fetch them would be:

“forstatur = Besparingslistan(forstatur, 1)”

“andratur = Besparingslistan(forstatur, 2)”

Kindly refer to the code below for better understanding:

% Initialize a cell array or matrix to store the pairs 

Turkonfig = []; 

 

% Iterate over rows of Besparingslistan 

for i = 1:size(Besparingslistan, 1) 

    forstatur = Besparingslistan(i, 1); 

    andratur = Besparingslistan(i, 2); 

     

    % Ensure indices do not exceed Kund_i_tur size 

    if forstatur <= length(Kund_i_tur) && andratur <= length(Kund_i_tur) 

        if Kund_i_tur(forstatur) ~= Kund_i_tur(andratur) 

            % Append the pair to the list 

            Turkonfig = [Turkonfig; forstatur, andratur]; 

        end 

    end 

end 

 

% Display the list of all qualifying pairs 

disp('Qualifying pairs:'); 

disp(Turkonfig); 

Kindly refer to the documentation of “for” loop for better understanding:https://www.mathworks.com/help/releases/R2021a/matlab/ref/for.html

I hope this will help!