How to write a code in M file for the variable name that constantly change with the file name

Hello,

Recently I created an M file (see below) to help me do FFT to a bunch of text files (with different names) containing waveforms. In each run, I want to use the variable (replaced with $$$$$$$$ as below) in the workspace that has the same name as the file name. How can I do it?

Thanks

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subject = {'JJG'} ;
modulation_depth = {'100'; '50'; '25'; '12.5'; '6.25'; '0'};
trace = {'1'; '2'};
for i = 1:length(subject)
  subject_char = char(subject(i));
  for j = 1:length(modulation_depth)
      modulation_depth_char = char(modulation_depth(j));
      for k = 1:length(trace)
          trace_char = char(trace(k));
          filename = strcat(subject_char, '_', modulation_depth_char, '_',
          trace_char, '.txt');
          load (filename);
          Y = fft($$$$$$$)/4096;
          FFT = 2*abs(Y(1:4096/2+1))
          FileName = strcat(subject_char, '_', modulation_depth_char, '_',
          trace_char, '_spec.txt');
          Save_Command = ['save ' FileName ' FFT -ascii'];
          eval(Save_Command);
      end
  end
end

Answer 1

[Walter Roberson]

Don't do it that way. Instead, when loading a text file (does not apply to .mat!)

YourVariable = load(filename);
Y = fft(YourVariable) / 4096;

Use whatever variable name is meaningful for your situation.