cash register with tax calculator

so im trying to create a program that enables me to calculate a total tax, however each purchase has a different tax rate and i have to add the respective tax rate to the purchase. so when i create a for loop thing are not adding up

load a02_data.mat
 
sub_tot = sum(purchases(:,1));
tax = 0;
 
L = length(purchases(:,1));
 
for ind = 1:L
    if purchases(ind,1) == 0
        sub_tot_0 = sum(purchases(ind,1));
         tax_tot_0= sub_tot_0 + tax_rate(1)*purchase(ind,1);
    
    elseif purchases(ind,1)== 1
        sub_tot_1 = sub_tot + purchases(ind,1);
        tax_tot_1 = sub_tot_1 + tax_rates(2)*purchase(ind,1);
        
    elseif purchases(ind,1) == 2
        sub_tot_2 = sub_tot + purchases(ind,1);
        tax_tot_2 = sub_tot_2 + tax_rates(3)*purchase(ind,1);
    end
end
tot = sum([tax_tot_0,tax_tot_1,tax_tot_2]);
disp(sub_tot);
disp(tot);

[Rik]

You can find guidelines for posting homework on this forum here. This time I edited your question for you. Next time, please use the tools explained on this page to make your question more readable.

Your question is currently a bit confusing. What do your variable mean? Where do they come from?

[fernando piedra]

my question is why is my for loop no giving me any input. when i run my program the disp(tot) doesnot display

[KALYAN ACHARJYA]

After execute the code, can you show the screnshot of the workspace?

[Rik]

Instead of posting screenshots, post your data and your code. You can attach a mat file with the paperclip icon.

Try to make a MWE so we can run your code without any other dependencies and can reproduce your issue.