How do I dynamically generate a variable name for individual saving of temporary data into separate MAT files?

16 views (last 30 days)
Ben
Ben on 15 Nov 2017
Edited: Ben on 15 Nov 2017
I'm aware of answers like this and this which do not like the idea of dynamic variable names. Perhaps it is too late in the day, but I am trying to save a single field of a structure as a single variable into a single MAT file, largely because of the large amount of data I have. I have tried the below, which mostly works.
filedate = datestr(now,'yyyymmdd');
for ii = 1:size(car, 1)
filename = [filedate '-' car(ii).NumPlate '-All-TT.mat'];
tempTT = car(ii).Timetable;
save(filename, 'tempTT', '-v7.3')
clearvars tempTT filename;
car(ii).Timetable = [];
end
clear ii car filedate;
However, when you then load these files back into MATLAB, the variable is named 'tempTT' which is extra confusing when they're all named the same, as I'm only using the tempTT variable to take the variable out of the car structure. The car structure contains three fields; name, number plate and timetable. This has previously been convenient, but the files with ALL the data are starting to get unwieldy.
I realise there may already be an answer to this, but I cannot see it. Any guidance, please.

Accepted Answer

per isakson
per isakson on 15 Nov 2017
Edited: per isakson on 15 Nov 2017
Doc on save says:
Save the fields of structure s1 as individual variables in a file
called newstruct.mat.
save('newstruct.mat','-struct','s1');
Something like ... ; replace
tempTT = car(ii).Timetable;
save(filename, 'tempTT', '-v7.3')
by
sas.( sprintf('Timetable_%02d',ii)) = car(ii).Timetable;
save( filename, '-struct', '-v7.3', 'sas' )
  1 Comment
Ben
Ben on 15 Nov 2017
Ah. I tried something like that with
temp(ii).(matlab.lang.makeValidName((['car-' car(ii).NumPlate]))) = car(ii).Timetable;
but just could not get it to work even with other configurations. I guess I just gave up trying myself too soon! Thanks for showing me the light. My code now works as intended.
%%Saving Data
filedate = datestr(now,'yyyymmdd');
for ii = 1:size(car, 1)
filename = [filedate '-' car(ii).NumPlate '-All-TT.mat'];
ix35.(matlab.lang.makeValidName((['car-' car(ii).NumPlate]))) = car(ii).Timetable;
save(filename, '-struct', 'ix35', '-v7.3')
clearvars ix35 filename;
car(ii).Timetable = [];
end
clear ii car filedate;

Sign in to comment.

More Answers (0)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!