Devide cell array into unequal length cells based on file name

With the following code I imported all of the .data files. All .data files of simulation 1 are located in folder 1 and all .data files of simulation 2 are located in folder 2.

%% Loading the data
rhoPart = 2540;

files = dir(fullfile(uigetdir,'\**\*.data*'));
[~,Index] = natsort({files.name});
files = files(Index);
expData = cell(length(files),1);
k = 1;
for i = 1:length(files)
    fid = fopen(fullfile(files(i).folder,files(i).name),'r');
    %% Reading the data
    % Read all the data from the file
    dataRead = textscan(fid,'%f %f %f %f %f %f %f %f %f %f %f %f %f %f','HeaderLines',1);
    frewind(fid);
    % Write headerline N, time, xmin, ymin, zmin, xmax, ymax, zmax
    runData{k} = strsplit(fgetl(fid), ' ');
    % Write only the x, y, and z components of the particles, particle radius,
    % z component+ particle radius and volume of the particle
    expData{k} = [dataRead{1}(:,1) dataRead{2}(:,1) dataRead{3}(:,1) dataRead{7}(:,1) dataRead{3}(:,1)+dataRead{7}(:,1) rhoPart*(4/3)*pi*(dataRead{7}(:,1).^3)];
    % Write only the vx,vy,vz of the particles and magnitude
    velData{k} = [dataRead{4}(:,1) dataRead{5}(:,1) dataRead{6}(:,1) sqrt(dataRead{4}(:,1).^2 + dataRead{5}(:,1).^2 + dataRead{6}(:,1).^2)];
    fclose(fid);
    k = k + 1;
end

This is the resulting workspace:

Simulation 1 (thus folder 1) contains 2745 .data files and simulation 2 (thus folder 2) contains 2741 files.

Is there a way to organize expData into a 2745x1 cell and 2741x1 cell without having to look up manually how many files each folder contains?

Answer 1

[Ameer Hamza]

Divide the data based on folder names. Something like this

%% Loading the data
rhoPart = 2540;
files = dir(fullfile(uigetdir,'\**\*.data*'));
[~,Index] = natsort({files.name});
files = files(Index);
folders = {files.folder};
folder_groups = findgroups(folders);
expData = cell(length(files),1);
k = 1;
for i = 1:length(files)
    fid = fopen(fullfile(files(i).folder,files(i).name),'r');
    %% Reading the data
    % Read all the data from the file
    dataRead = textscan(fid,'%f %f %f %f %f %f %f %f %f %f %f %f %f %f','HeaderLines',1);
    frewind(fid);
    % Write headerline N, time, xmin, ymin, zmin, xmax, ymax, zmax
    runData{k} = strsplit(fgetl(fid), ' ');
    % Write only the x, y, and z components of the particles, particle radius,
    % z component+ particle radius and volume of the particle
    expData{k} = [dataRead{1}(:,1) dataRead{2}(:,1) dataRead{3}(:,1) dataRead{7}(:,1) dataRead{3}(:,1)+dataRead{7}(:,1) rhoPart*(4/3)*pi*(dataRead{7}(:,1).^3)];
    % Write only the vx,vy,vz of the particles and magnitude
    velData{k} = [dataRead{4}(:,1) dataRead{5}(:,1) dataRead{6}(:,1) sqrt(dataRead{4}(:,1).^2 + dataRead{5}(:,1).^2 + dataRead{6}(:,1).^2)];
    fclose(fid);
    k = k + 1;
end

expData_partition = splitapply(@(x) x, expData, folder_groups);

[Tessa Kol]

Thank you for your reply. Unfortunatly, I got the following error:

Error using splitapply (line 101)
The data variables must have the same number of columns as the vector of group numbers. The group number vector has 5486 column(s), and data
variable 1 has 1 column(s).

Error in Untitled (line 26)
expData_partition = splitapply(@(x) x, expData, folder_groups);

When I deleted the following line of code:

expData = cell(length(files),1);

I got yet another error:

Error using splitapply (line 132)
The function '@(x)x' returned a non-scalar value when applied to the 1st group of data.

To compute nonscalar values for each group, create an anonymous function to return each value in a scalar cell:

	@(x){x}

Error in Untitled (line 26)
expData_partition = splitapply(@(x) x, expData, folder_groups);

[Tessa Kol]

Never mind. The curly brackets were missing, thus it should be:

expData_partition = splitapply(@(x) {x}, expData, folder_groups);

[Ameer Hamza]

Yes, I wrote that line based on guess of the content of expData. I am glad that it eventually worked!