Attempted to access d(2); index out of bounds because numel(d)=1.

Hello, I'm kinda new to MatLab and not much experienced in coding in general and would like to ask for some help. I am trying to create a matrix:

 t = [mean(d1), mean(d2),... , mean(d18)];

d1, d2 etc are all seperate matrices of size of 1 row and 5 columns except of d1 which has 3 columns. Although I currently have it set up as above, I want a more tidy way to also get some sort of experience so I tried this:

 i=1;
while i < 19;
    f(i) = mean(d(i));
    i = i+1;
end
t = f(1:18);

But I got this error: Attempted to access d(2); index out of bounds because numel(d)=1. Is it because what I wrote does not make sence? If yes, how can I correct it and in short what does that error mean? Thanks in advance.

[Stephen23]

Your code will be much simpler, more reliable, and much more efficient if you just use indexing into one variable instead of trying to create lots of separate variables.

https://www.mathworks.com/help/matlab/matlab_prog/string-evaluation.html

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

Answer 1

[Walter Roberson]

http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F

[Walter Roberson]

D = {d1, d2, d3, d4, d5, d6, d7, d8, d9, d10, d11, d12, d13, d14, d15, d16, d17, d18};
for i = 1 : length(D)
  f(i) = mean(D{i});
end

or

D = {d1, d2, d3, d4, d5, d6, d7, d8, d9, d10, d11, d12, d13, d14, d15, d16, d17, d18};
f = cellfun(@mean, D);