For loop with variable

Hi I'm trying to build a for loop with variables only however it is not working it only gives me one correct value and then the other two are incorrect. The only one correct is the one where it says answer Idk what to do to make the other two work.

[Scott MacKenzie]

Why are you trying to use a for-loop? What you are trying to do?

Answer 1

[Cris LaPierre]

Ch 13 of MATLAB Onramp covers for loops.

[andrea vivas]

Yeah it still doesnt help me because they only use vectors with numbers and I'm trying to do it with variables.

[Cris LaPierre]

You might have to do a little application of what you learn.

Answer 2

[DGM]

If you do this:

for n=1,2,3
    % do thing
end

It's the same as doing

for n=1
    2 % these do nothing but print to console
    3
    % do thing
end

Your loop will cycle only once. Instead, use

for n=[1 2 3]

because that actually specifies a vector.

Lastly, your loop doesn't actually store any values. It just dumps the result to console. If you intend to use it for something, you'll have to assign the output to a variable.

[andrea vivas]

Perfect this solve it, and how do you assing the output to a variable?

[DGM]

Consider the slightly more elaborate example:

inputvector=[12 564 32 9 6.2]; % specify inputs

outputvector=zeros(size(inputvector)); % preallocate outputs
for n=1:numel(inputvector) % define iterator based on input length
    outputvector(n)=inputvector(n)/4; % store the output
end

Of course, if all you're doing is dividing by four and nothing else, this entire example can be simplified to:

inputvector=[12 564 32 9 6.2];
outputvector=inputvector/4; 

Nothing in the loop is dependent on prior results, so you don't need it.