Automatically load a csv file from a folder

I have a database (Male_Data_Dhort_QT). Within the database I have a column called FileName which (as you assumed) has names of files that I have stored in a folder called ECGData. I have a line that randomly selects a filename.

random_MaleShortName = datasample(Male_Data_ShortQT.FileName,1)

I get a 1x1 categorical result with the name of the file.

I want to create a function that automatically gets that value and searches for the file in the ECGData folder. I'd highly appreciate any help. Thanks

[Kojiro Saito]

Do you want to get file names from ECGData folder, then run datasample function with file names as input?

[Walter Roberson]

As written they want the opposite, that the database is to be the primary source for information about which files can be selected, and once a name has been chosen from the database then the file is to be opened.

Storing the names in a variable can be faster than dir() each time.

[Daniela Valdez]

No, first I randomly get a file (FileName with datasample) and I want to open that file, which it is on a different folder named ECGData

[Image Analyst]

What is your definition of "automatic"? And of "manual". If you have to have a line of code read in the file, is that automatic? Do you need some sort of timer that periodically gets a random filename from the database?

What is the database? Is it an actual database where you use the Database Toolbox? Or is your database just a folder of files, or a table of values?

And not sure why the filename is a categorical variable instead of a string or character array. What are the categories?

Answer 1

[Walter Roberson]

EEGDIR = '/Users/roberson/Plan9/Dhort/ECGData';

tries = 42;
found = true;
for trynum = 1 : tries
  random_MaleShortName = datasample(Male_Data_ShortQT.FileName,1);
  filename = fullfile(EEGDIR, string(random_MaleShortName)+".csv");
  if exist(filename); found = true; break; end
  fprintf('Oh, missing file "%s"\n', filename);
end

if ~found
    fprintf('Bummer! No file found in %d tries! Giving up!\n', tries);
    return;
end

%at this point filename refers to a file that has been verified to exist.