Retrieve data from several folders and structures

Hi,

I have data organized in folders. Each folder contains a structure. I need to go through all the folders retrieving some of the fields from the structures, and organize the data in a new structure.

The folders are folder_1, folder_2.....folder_n. Each folder contains a structure called motion_data. I need to extract the information from motion_data.response.X, which is a 20x15 double.

I would like to structure the extracted data in the following manner:

Newstructure.folder_1.responseX

Newstructure.folder_2.responseX

etc.

Can I get help with this? I'm not sure waht is an efficient way to go through all the folders and retrieve the info to save it in the new structure.

Thanks!

[Stephen23]

Question is continued here:

https://www.mathworks.com/matlabcentral/answers/438595-retrieve-data-from-several-structures-and-folders

Answer 1

[Gareth]

If I understand correctly you have data files in different folders and you want to take subset of that data and reorganize it in a new structure.

To solve this there are a couple of things you can try: (I am on a mac and R2018b so the slashes might be different for you).

a = dir('**/*.mat'); % I am assuming the data you have in each folder is a type *.mat but if it is something else change this
newStruct = []
for i = 1:size(a,1)
    % Read data from each file in which ever way you do today
    mydata = load(a(i).File)
    [~,d,~] = fileparts(a(i).folder)
    newStruct = setfield(newStruct,d,mydata)
end

Please note that this will kind of work, depends on how you store your data in each of the folders but the key things here are:

• fileparts gets information from dir and parses the folders
• setfield is how you programatically add fields to structures

Hope this helps you

[Isma_gp]

Hi, this was very helpful and I've been using it.

I have now to retrieve data from a structure in a similar fashion, however, the problem is slightly different. Do you think you could help me with a similar solution?

The data is still organized in folders.

The folders are folder_1, folder_2.....folder_n. Each folder contains a structure called moo_data. Each structure contains several structures (file_1, file_2, file_3...etc). Each of these structures contains a double (24x20) called response that I need to extract.

I would like to structure the extracted data in the following manner:

Newstructure.folder_1.response

Newstructure.folder_2.response

[Gareth]

When you say each folder contains moo_data, is that a mat file in each folder that when you load it, you get a structure moo_data? This might be a good candidate for a new Answer question:)

[Isma_gp]

Reformulated here:

https://se.mathworks.com/matlabcentral/answers/438725-retrieve-data-from-several-structures-and-re-organize-a-new-structure