Matlab: Automatically create cell array with name with meaning

Question

I would like to name variable (type double) in the following way:

k0 = D(1,1);
k1 = D(2,2);
k2 = D(3,3);
k3 = D(4,4);
k4 = D(5,5);
k5 = D(6,6);
k6 = D(7,7);
k7 = D(8,8);
...

up to k99 automatically using for loop. So I see that I should use array or cell instead of double variable using eval as it is slow. But if I should use array or cell instead of double variable, I have to start at k{1} or k(1), which loses the meaning as I want exactly that k0 refers to D(1,1), i.e. the number in my variable is 1 less. How do I create meaningful cell name like k{0}?

Also, say I have an array A. There are also some times i need meaningful variable name, such as

c111 = A(1)*A(1)*A(1)
c222 = A(2)*A(2)*A(2)
c333 = A(3)*A(3)*A(3)

How can I create c{111} efficiently using for loop?

Answer 1

Answer to 1st Question:-

D=randn(100);    % A matrix of random elements of size 8x8
for m=0:99
    assignin('base', ['k' num2str(m)], D(m+1,m+1))
end

Answer to 2nd Question:-

A=randn(1,3);    % An array of 3 random elements 
for n=1:3
    assignin('base', ['c' num2str(111*n)], A(n)^3)
end 

Comments:-
You've stated that you need variables like k0,k1,k2,... and c111,c222,c333 but you're asking how to create k{0}, k{1},k{2},... and c{111},c{222},c{333}. As far as your need is concerned, I have given answer to it. Regarding the latter, k{0} is never possible and c{111},c{222},c{333},... don't make good sense without using any of the first 0:100 values and then 112:221 values and so on. Although you can do it using:

A=rand(1,3);       % An array of 3 random elements 
c{333} = 0 ;       % Pre-allocation
for p=1:3          % Since you want to use a 'for loop'
  c{111*p} = A(p)^3;
end

And regarding the requirement that you made in the comment in these words "I also have some variable using negative index", you can never have variables in the negative index. If you mean you want to create variables with names like k-1, k-2,... etc, it is not possible. An alternate way is to use k_1, k_2,... etc but then as you said in the question "k0 refers to D(1,1), i.e. the number in my variable is 1 less". It means k_1 will refer to D(0,0) and so on which is again an invalid thing for MATLAB.

Recommendation:-
You really need to modify your code.

Answer 2

Use structures:

D = rand(21);
c = 1;
for k = -10:10
    if k<0
        s.(['k_' num2str(abs(k))]) = D(c,c);
    else
        s.(['k' num2str(k)]) = D(c,c);
    end
    c = c+1;
end

This will give you a structure like:

s = 

     k_10: 0.51785
     k_9: 0.90121
     k_8: 0.40746
     k_7: 0.092989
     .
     .
     k_1: 0.75522
     k0: 0.55257
     k1: 0.28708
     .
     .
     k9: 0.94182
     k10: 0.2124

and don't use eval...