error writing .txt to /ecat_testing/steps folder

[fishpm]

Describe the bug

If pet image created by ecat2nii requires rescaling, then ecat2nii.m tries to write scaling info to a .txt file saved to a folder (ecat_save_steps_dir) that is .../PET2BIDS/ecat_testing/steps, which does not exist in current PET2BIDS structure. Seems to me there are at least two straight-forward solutions: 1) write .txt file to .../PET2BIDS/matlab/ecat_testing, which does exist in current PET2BIDS structure, or 2) mkdir(ecat_save_steps_dir) if it does not exist. I am uncertain whether one is preferred for reasons about which I am unaware.

l. 202 - 220 of ecat2nii.m:

% rescale to 16 bits
rg = max(img_temp(:))-min(img_temp(:));
if rg ~= 32767 % same as range(img_temp(:)) but no need of stats toolbox
MaxImg = max(img_temp(:));
img_temp = img_temp/MaxImg*32767;
Sca = MaxImg/32767;
MinImg = min(img_temp(:));
if (MinImg<-32768)
img_temp = img_temp/MinImg*(-32768);
Sca = Sca*MinImg/(-32768);
end
% save scaling factor to file located at ecat_save_steps_dir/8.5_sca_matlab.txt
fid = fopen([ecat_save_steps_dir filesep '8.5_sca_matlab.txt'],'w');
fprintf(fid,'Scaling factor: %10e\n',Sca);
x = mh.ecat_calibration_factor * Sca;
fprintf(fid,'Scaling factor * ECAT Cal Factor: %10.10f\n',x);
fclose(fid);
end

To Reproduce
code: ecat2nii(filename{1},metadata);
error: Invalid file identifier. Use fopen to generate a valid file identifier.

Desktop (please complete the following information):

• OS: Linux
• matlab r2023a

[CPernet]

@bendhouseart I do not remember writing this - did you do that?
@fishpm looks like we did that to test stuff as we had some issues -- and IMO that is not something user need to know (Claus does that all the time)

[fishpm]

good to know, seems straight-forward to comment out/remove writing to the .txt file. i will make the pull request.