Searching Folder for Variable File Name

I am trying to combine the data from several different files to analyze together. The data as of right now is in individual csv files that are in a common folder. The ultimate goal is to be able to store the information from each file in arrays to be called on when needed. All of the files are name the same with the exception of the group and blade number. It looks something like "Lab-Proc-RPM-G#_B#_Summary". G ranges 1:19 and B ranges 1:4. I have created a for loop to create the individual file names hoping that I could use dir to search the location for these files but when the variable "fileName" is used to dir, it does not use the variable it stores but the variable name to search.

I have tried to convert the string class of fileName to a character but that didn't do anything; I have tried to use just the "G#_B#" portion of the file name to search just for that; I have added the wildcard * in just about everyway I can; i have added this file location to the path in the current folder box

Another weird thing is that if I copy part of the file name created and outputted to the command window and paste it into the search box of my file explorer, it will find the file. If I copy the entire file name that is created, both string and char, to the search box the file is not found. Could this be a class type issue between the output of the fileName variable and the required class in the search bar?

Proc2_500_Dir = "C:\Users\jlange\OneDrive - Rest of Path"

for i = 1:19 %Number of Groups

i_pad = sprintf('%02d',i);

for j = 1:4 %Number of Blades per group

j_pad = sprintf('%02d',j);

fileName = "G" + i_pad + "B" + j_pad

%fileName = "57306-Proc2 - 500 Steps-sec_G" + i_pad + "_B" + j_pad + "_Summary"

fileName = convertStringsToChars(fileName)

dir fileName

end

end

Update: The code was updated to output the fileName as G#_B#

[Stephen23]

As Jan wrote, you need to use function syntax, not command syntax:

https://www.mathworks.com/help/matlab/matlab_prog/command-vs-function-syntax.html

Answer 1

[Jan]

Use the functional form:

dir(fileName)

Omitting the parentheses is equivalent to:

dir('fileName')

A simplified version of your code:

Proc2_500_Dir = "C:\Users\jlange\OneDrive - Rest of Path"
for i = 1:19     % Number of Groups
    for j = 1:4  % Number of Blades per group
        fileName = sprintf('G%02dB%02d', i_pad, j_pad);
        dir(fullfile(Proc2_500_Dir, fileName))
    end
end

[Brandon Lange]

Thank you for this response. I tried using the function form both with and without paranthesis and wildcards.

I ended up working around the dir search and just checked if the file was in the folder and if it was to read it and write it to a 3D matrix. The check may not be strictly necessary as I already know that these files exist in the folder but it started as a sanity check that seems like a "nice to have" feature

Proc2_500_Dir_Info = dir(Proc2_500_Dir);

%% Loops read each file and place each group in a (5,10,4) matrix. The four pages of each matrix indicates 
%  the blade number for each group. The fifth blade for each 
for i = 1:19 %Number of Groups
    i_pad = sprintf('%02d',i);
    for j = 1:4 %Number of Blades per group
        j_pad = sprintf('%02d',j);
        ident = "G" + i_pad + "_B_" + j_pad; %blade identifier
        fileName = "57306-Proc2 - 500 Steps-sec_G" + i_pad + "_B" + j_pad + "_Summary.csv";
        fileNameChar = convertStringsToChars(fileName);
        check = any(Proc2_500_Dir_Info(3).name == fileNameChar);
        if check == 1
            switch i
                case 1
                    G01(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 2
                    G02(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 3
                    G03(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 4
                    G04(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 5
                    G05(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 6
                    G06(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 7
                    G07(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 8
                    G08(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 9
                    G09(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 10
                    G10(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 11
                    G11(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 12
                    G12(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 13
                    G13(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 14
                    G14(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 15
                    G15(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 16
                    G16(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 17
                    G17(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 18
                    G18(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6');
                case 19
                    G19(:,:,j) = readmatrix(fileName, 'Range', 'B2:K6'); 
            end
        end
    end
end

[Jan]

Another approach (see: FAQ: How can I process a sequence of files?)

G = {};
FileList = dir(fullfile(Proc2_500_Dir, '*_Summary.csv'));
for k = 1:numel(FileList)
    FileName = FileList(k).name;
    File     = fullfile(FileList(k).path, FileName);
    index    = sscanf(FileName, 'G%d_B_%d', 2);
    G{index(1)}(:, :, index(2)) = readmatrix(File, 'Range', 'B2:K6');
end

This avoid the hiding of indices in the names of the variables. The later access of the array is much easier tham having a pile of numbered variable names.

Actually this should not work relaibly:

any(Proc2_500_Dir_Info(3).name == fileNameChar)

The == operator performs an elementwise comparison in case of CHAR vectors. In addition you are using the 3rd file of the folder only.