Change variable name in plot

I have these variables as a double:

time; run_0; run_1; run_3; ...; run_23

how can I plot them without rewriting everytime the function plot?

The idea is:

for i = 0:23
    plot(time, run_i); %index 'i' to change dynamically
    hold on
end

I do not know how to write the index 'i'.

[KSSV]

Why did you name them as run_0, run_1, etc??

Instead, save them into an array.

[Stephen23]

"I do not know how to write the index 'i'."

That is not an index, it is a pseudo-index which is part of the variable name, which makes it much harder to process your data. Acessing variable names dynamically is slow, complex, inefficient, and best avoided.

If you had used an actual index (as you should have) then this task would be very simple and efficient:

https://www.mathworks.com/help/matlab/matlab_prog/access-data-in-a-cell-array.html

[Gabriele Curcio]

Yes I know that is not an easy task, but regrettably the log of my device is structured as said before.

And at the moment, changing the log structure is harder and slower than trying to find a solution on matlab.

By the way, I did not get your answer.. am I supposed to follow the indications of the function in the link?

[Stephen23]

@Gabriele Curcio: how did you import this data into the MATLAB workspace? Most likely that is the best place to handle this situation. For example, did you import those variables using LOAD ?

" I did not get your answer.. am I supposed to follow the indications of the function in the link?"

The link shows you how simple this task would be if you used indexing.

[Gabriele Curcio]

Yes yes, I know it would be easier, but at the moment I am trying to find a workaround to that.

Yes I have imported these variables using LOAD.

[Stephen23]

"Yes I have imported these variables using LOAD."

Good, now we are getting somewhere. Always LOAD into an output variable:

S = load(..)

All of the loaded variables are fields of the scalar structure S. Note that you can easily obtain the fieldnames

C = fieldnames(S)

and then loop over them (or just generate them yourself e.g. using SPRINTF) and use dynamic fieldnames, for example to access the 2nd field of the structure:

S.(C{2})

See: https://www.mathworks.com/help/matlab/matlab_prog/generate-field-names-from-variables.html

How many variables are in each MAT file? (Or are you unfortunately using LOAD to import textfiles?)

Please upload your data files (two or three, not all) by clicking the paperclip button.

[Gabriele Curcio]

Ok, I manage to get the expected result! Thank you very much

Answer 1

[Constantino Carlos Reyes-Aldasoro]

As mentioned before, this is not the best way to handle your data, BUT you are where you are, so to be able to use the names run_0, run_1, etc you need to concatenate strings:

for i =0:10
    name = strcat('run_',num2str(i))
end

name = 'run_0'

name = 'run_1'

name = 'run_2'

name = 'run_3'

name = 'run_4'

name = 'run_5'

name = 'run_6'

name = 'run_7'

name = 'run_8'

name = 'run_9'

name = 'run_10'

Further, do not use i for a counter, i can be used for imaginary numbers, better to use a sensible name like "counterRuns" or something that has a meaning.

Hope this solves your problem

[Stephen23]

"...you need to concatenate strings"

A more efficient approach is to use SPRINTF:

sprintf('run_%d',i)

or use the STRING class:

"run_" + i