Trying to add data pulled from trials subfolders into a table and add a column in that table that labels the data with the trial that is came from

I have code right now that after the user selects a file there is are mutiple subfolders labeled with trial numbers. Within the each trial folder is anotehr subfolder "Data" that matlab pulls in as a text file "imudata.txt" and bring it into the workspace as a table.

the file structure is like this

• pt_01 folder
• - Trial 1
• -> Data
• imudata.txt
• - Trial 2
• -> Data
• imudata.tx
• - Trial 3
• -> Data
• imudata.txt

the code is:

P = uigetdir('C:\user\project1\');
F = fullfile(P,'Trial*','Data','imudata.txt');
S = dir(F);
for k = 1:numel(S)
    F = fullfile(S(k).folder,S(k).name);
    T = readtable(F); % pick a suitable file importing function and options.
    S(k).data = T;
end
    

I want the data to add all of the data into a table with other data from each trial and have create a colum in the table that labels which trial the data came from. So it looks something like this:

Here is what im thingking so far but im not sure if it is right.

Creating a table with Data from Each Trial
for i= 1:numel(T)
    Table = [S(i).data,CDData(i).data]
    Trial = i
    Table_i= addvars(Table,Trial);
end

Any help is greatly appreciated

[Stephen23]

Context:

https://www.mathworks.com/matlabcentral/answers/2080416-how-to-have-a-user-select-a-file-and-then-matlab-automatically-go-into-multiple-subfolders-and-pull

Answer 1

[Voss]

P = uigetdir('C:\user\project1\');
F = fullfile(P,'Trial*','Data','imudata.txt');
S = dir(F);

for k = 1:numel(S)
    
    F = fullfile(S(k).folder,S(k).name);
    T = readtable(F);
    
    trial_name = regexp(S(k).folder,'\\(Trial.*)\\','tokens','once');
    new_data = repmat(trial_name,size(T,1),1);
    T = addvars(T,new_data,'NewVariableNames',{'Trial'},'Before',1);
    
    S(k).data = T;
    
end

[Isabelle Museck]

Hi there thnak you for your help! I just tried running this code and go this error in the T=addvars line:

'Error using . "

To assign to or create a variable in a table, the number of rows must match the height of the table.

Error in tabular/addvars (line 184)

b = move(b).dotAssign(newvarnames{ii},varargin{ii}); % b.(newvarnames{ii}) = varargin{ii}

Is this an issue with the new_data variable, do you have and suggestions on how to fix this?

Thank you so much

[Isabelle Museck]

It also says that trial_name and new_data are a 0x0 cell so maybe their is an issue with those variables

[Isabelle Museck]

I just fixed that issue never mind! It left me with a 1x10 structue (with data from all 10 trials) stored in S in the workspace shown here. It there any way to vertically concatenate all this data into one table outside the loop?

[Isabelle Museck]

[Voss]

"[Is] there any way to vertically concatenate all this data into one table outside the loop?"

% after the loop:
T = vertcat(S.data)