I need a program to read data from a single file

I'm doing a research project for my space weather project, and I have a lot of data files (.21I) separated by folders. With the function "dir" I can now see all the files as a list, but now I need to be able to read the data from a single file. How do I do it?

[Mathieu NOE]

hello

how are the data structured in those files , can you edit them ?

[Luís Mira]

Well, so far I've got this:

%% Código Matlab Projeto

%tentativas

close all
clear all
clc

a = 'C:\Users\box\Desktop\Projeto Luis\Dados\2021';

d=dir('**/*.21I');

b=struct2cell(d);

w=b(:,1);

which gives me this:

and the structure is the following picture:

And I really don't know what I have to do now.

[Mathieu NOE]

is this a homework ? did you get any info / advice / request about what you have to do ?

[Luís Mira]

It's for a project I'm working on. Basically, the files are from TEC data (total electron content) and they're separated by 15 minutes from each other. Since there's 8117 files, I was told to build a program to easily choose what I want and then I need to be able to read the files.

Answer 1

[Jan]

Omit the brute clearing header:

close all
clear all
clc

This is not useful in productive code and I cannot imagine why it is recommended such frequently to beginners.

Use a function instead, to keep the workspace clean.

Folder   = 'C:\Users\box\Desktop\Projeto Luis\Dados\2021';
FileList = dir(fullfile(Folder, '**', *.21I'));
for iFile = 1:numel(FileList)
    File = fullfile(FileList(iFile).folder, FileList(iFile).name);
    % Now import this File as needed:
    ...
end

See: FAQ: process a sequence of files

[Luís Mira]

Ok, thanks mate. I'm still learning and I was told since the beggining to do it so, that's why I do it everytime.

[Jan]

Yes, it happens frequently that teachers tell their students to use this brute clearing header. clear all removes all loaded functions from the memory such that they have to be read again from the slow disk. This wastes a lot of time without any benefits. I'm afraid the teachers simply repeat what they have been told when they have been students, although they do not understand, what the code does. This is called "cargo cult programming", which is a widespread programming anti-pattern.