Reading a large csv and converting to timetable

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Louise Wilson 2020-4-30

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评论： Louise Wilson 2020-8-26

I have a large .csv (7179x72001) where the first column is filled with datenums and the remaining columns are numerical values. The only way I have been successful in reading this data is by using csvread() and it usually takes about 20 minutes.

I have a second .csv which contains the same values but in datetime format and I would like to compare the two.

Is it possible to convert the first column in the large file so that the values are datetimes, and then in turn convert this to a timetable?

I can do this but I only want to convert the first column, not the whole dataframe:

newtable=datetime(dataframe, 'ConvertFrom', 'datenum');

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Louise Wilson 2020-4-30

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I have just tried this:

thetable=readtable(fullfile(foldername,'001Noises_5103_PSD_1sHammingWindow_50%Overlap_output.csv'));
datetime(thetable.Var1,'ConvertFrom','datenum');
head(thetable)

This doesn't give any errors but the contents of the first column remain as datenums.

Louise Wilson 2020-4-30