How to iterate through the struct char to label a new struct correctly?

4 views (last 30 days)
I know that when I create a structure, e.g.
fruits(1).apples = data1;
fruits(1).bananas = data2;
I obtain a structure with two fields, and each fields having their respective data1 and data2. What I am attempting to do is loosely based on this.
The same way that above I have labelled my fields "apples" and "bananas", I have a 9x1 field with the names of what I shall label my data fields (shown in the code below).
% List of all the desired files in the folder
%the names of my files are: sample_1, sample_10, sample_13, etc.
filePattern = fullfile(myFolder, 'sample*.mat'); %search for files
theFiles = dir(filePattern);
theFiles = natsortfiles(theFiles); %arrange the files names in numerical order
%the data is a 1x30 structure
for x = 1 : length(theFiles)
baseFileName = theFiles(x).name; %e.g. for x =1 , baseFileName = 'sample_1.mat'
data(1).baseFileName =nk('ref_K15rapidscan.mat','base_K15rapidscan.mat',baseFileName);
end
%nk is a function to process data and to give other data back. The data resulting from this is a 1x30 struct with 2 fields
The problem is that I cannot simply write "data(1).baseFileName", as MATLAB doesn't recognise that baseFileName is a different char each time on the last line
data(1).baseFileName =nk('ref_K15rapidscan.mat','base_K15rapidscan.mat',baseFileName);
How can I end up with something like the image below?
(The image might make it look like I actually got it to work, but really I just changed the name of the fields (apple, pear banana, etc) by hand to sample_1, etc.
  2 Comments
Goncalo Costa
Goncalo Costa on 22 Feb 2023
This is just a function written by a colleague to process some data and give me some data back as a result. The data resulting from this function is in the form of a 1x30 struct with 2 fields as shown in the last image (I will rewire this onto the questions).

Sign in to comment.

Accepted Answer

Goncalo Costa
Goncalo Costa on 22 Feb 2023
I ended up solving it and I am placing here my answer:
% List of all the desired files in the folder
filePattern = fullfile(myFolder, 'sample*.mat'); %search for files
theFiles = dir(filePattern);
theFiles = natsortfiles(theFiles); %name of files and other info
%all data placed into a single struct w/ x fields
for x = 1 : length(theFiles)
baseFileName = theFiles(x).name;
[path, name, ext] = fileparts(theFiles(x).name);
data(1).(name) =nk('ref.mat','base.mat',baseFileName);
end
  2 Comments
Stephen23
Stephen23 on 22 Feb 2023
Edited: Stephen23 on 22 Feb 2023
Not that this is fragile data design: there are many characters which are valid in filenames which are not valid in fieldnames. When you get such a character, this code will fail.
For much more robust code which does not duplicate data in extra variables, see the answer I gave you earlier:

Sign in to comment.

More Answers (2)

Oguz Kaan Hancioglu
Oguz Kaan Hancioglu on 22 Feb 2023
You can use eval function to use char arrays or strings as a matlab command.
data(1).baseFileName =nk('ref_K15rapidscan.mat','base_K15rapidscan.mat',eval(baseFileName));
  1 Comment
Goncalo Costa
Goncalo Costa on 22 Feb 2023
When I use this it tell me the following error
Unable to resolve the name sample_10.mat.
I think I need to separate the .mat from the rest of the files names, I tried to do this using fileparts, but it doesn't work either.

Sign in to comment.


Voss
Voss on 22 Feb 2023
for x = 1 : length(theFiles)
baseFileName = theFiles(x).name; %e.g. for x =1 , baseFileName = 'sample_1.mat'
[~,fn,~] = fileparts(baseFileName);
data(1).(fn) = nk('ref_K15rapidscan.mat','base_K15rapidscan.mat',baseFileName);
end

Categories

Find more on Structures in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!