How to calculate standard deviation in double for loop?

for j = 1:length(EC)
    for k = 1:length(Reff)
        eval(['depri',num2str(j),num2str(k),'=','(depi',num2str(1),num2str(j),num2str(k),')./(depi',num2str(2),num2str(j),num2str(k),');']);
    end
end
deprir1 = [depri11(10) depri12(10) depri13(10) depri14(10) depri15(10)];
deprir2 = [depri21(10) depri22(10) depri23(10) depri24(10) depri15(10)];
deprir3 = [depri31(10) depri32(10) depri33(10) depri34(10) depri15(10)];
deprir4 = [depri41(10) depri42(10) depri43(10) depri44(10) depri15(10)];

I want to write a function to calculate the standard deviation in the function 'depri' written in the eval expression for both of the loop indices, j and k. So after that, I would be able to calculate the standard deviaiton in each value of depri (deprir1,deprir2,.......) at each point (depri11(10), depri12(10),.....).

Answer 1

[James Tursa]

The short answer is don't do that. This style of programming has many problems. See this link for alternatives:

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval?s_tid=srchtitle

[Wiqas Ahmad]

Thank you for your suggestions. I will adopt the alternatives to eval function but my program is too lengthy and will consume more time because I posted here just a portion of my program. On the other hand, this is a recommended program by my supervisor to modify to obtain my results, otherwise I'm not enough expert in programming. What I needed now is to learn how can we calculate the standard deviation in this case using double forloop? After all, I will improve my program to be more efficient.