How to change string name?

Hey!

I have a function e.g. y=a*x.

How can I change later string name of y to y306 or sth like that?

[TADA]

How can I change later string name of y to y306

do you mean change the name of your variable from y to y306?

[Stephen23]

"How can I change later string name of y to y306 or sth like that?"

Dynamically changing variable names is one way that beginners force themselves into writing slow, complex, buggy code that is hard to debug. Read this to know why:

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

Rather than forcing a pseudo-index into a variable name, you should use a real index with one array, or perhaps a structure or a table.

[Elzbieta Trynkiewicz]

Thank you for your comment but could you explain me more or help with following problem?

I created this question since I have such kind of problem: I tried to load multiple data which was previously saved like a 'y'; but all of these, despite the different external filename, they have the same name of "internal" variable and they are overwriting.

[Stephen23]

"I tried to load multiple data which was previously saved like a 'y'; but all of these, despite the different external filename, they have the same name of "internal" variable and they are overwriting."

Aaah, that is an entirely different question to what you asked about: http://xyproblem.info/

Answer 1

[Stephen23]

The solution is to simply use indexing. For example, you could put all of your imported data into one cell array. You did not give much information in your question (e.g. the file format, what function you are using to import the data, the data class, whether you generate the name with sprintf or use dir to obtain the names of existing files, etc), so I will show an example that imports data from .mat files using load:

S = dir('*.mat');
N = numel(S);
C = cell(1,N); % preallocate.
for k = 1:N 
    C{k} = load(S(k).name);
end
A = [C{:}] % optional, create non-scalar structure.

Then all of the imported data will be available in the cell array C or (even better) the non-scalar structure A:

https://www.mathworks.com/help/matlab/matlab_prog/access-multiple-elements-of-a-nonscalar-struct-array.html

If the loaded .mat files only contain one (or a few) variables that you need, you can easily access them inside the loop and put that data into on (or a few) array, e.g.:

S = dir('*.mat');
N = numel(S);
C = cell(1,N); % preallocate.
for k = 1:N 
    T = load(S(k).name);
    C{k} = T.y;
end

Feel free to adapt the class and size to suit your data: depending on your data you could import into a numeric/char/string array, with columns/rows to suit number of variables, etc..

You should read this too:

https://www.mathworks.com/help/matlab/import_export/process-a-sequence-of-files.html

[Elzbieta Trynkiewicz]

Thank you very much for your help!!!