How to add a column for data in datastore

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Saif Aljanahi
Saif Aljanahi 2021-3-27
回答： Khushboo 2022-11-4
I have a data store that holds 2,700 files, theses files are activities such (standing, walking, lying,...and etc).
the datastore contains all these files, all files having 3 columns (acceleration of x,y,z).
I want to write a code that can add a fourth column to this datastore depends on the original file name that I have added earlier to this datastore.
I want to do this, to make labeling and prepare my data for classification.

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回答（1 个）

Khushboo
Khushboo 2022-11-4
Hello,
As datastore simply reads the data from a file to a table, you will have to write the modified table back to the datastore. This can be done using something like this:
while hasdata(currentDs)
[T, info] = read(currentDs);
% Add a new column to the end of the table
T.newCol = newColumnToBeAdded; %ensure that it is a cell array
%Write the new modified file back the table
filename = ['newfolder/modifiedfile_', num2str(info.Offset), '.csv'];
writetable(T, filename);
end
newDs = datastore('newfolder/*.csv');
Hope this helps!

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