years read in as 18 instead of 2018; how do I add 2000 years?

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Heidi Hirsh
Heidi Hirsh on 27 Sep 2019
Edited: Adam Danz on 4 Oct 2019
I checked similar questions asked and it seems like the previous answers aren't quite what I am looking for. I have a csv file with a column of date and time. The dates are all mm/dd/18 not mm/dd/2018 so the years read into matlab as 18 not 2018. How can I add 2000 to the year in my timestamps (after importing to matlab). I tried using the addtodate function to add 2000 years (see below) but I got an error that says "Date number must be a numeric scalar." I'm not sure which value is my date number. I am sure there are several ways to do this. I am just looking for a straightforward way to save my year data correctly so that the matlab timestamps are correct. Thank you!
I have also attached the csv file here.
mba = readtable('2018_irradiance.csv');
irrad = mba.PAR;
timestamp = datenum(mba.PST);
times = addtodate(timestamp, 2000, 'year');

Accepted Answer

Adam Danz
Adam Danz on 27 Sep 2019
Edited: Adam Danz on 2 Oct 2019
Read the data in as text rather than datetime by using the DateTimeType parameter of readtable(). Then specify the datetime format in datenum().
mba = readtable('2018_irradiance.csv','DateTimeType','text');
irrad = mba.PAR;
timestamp = datenum(mba.PST,'mm/dd/yy HH:MM');
However, I recommend that you do not split up the variables stored in the mba table. Tables are a great way to keep data organized. To change the date format in the table, use datetime with a specified input format (*note that it's a different format than datenum).
mba = readtable('2018_irradiance.csv','DateTimeType','text');
mba.PST = datetime(mba.PST,'InputFormat','MM/dd/yy HH:mm');
% display first few rows
ans =
8×2 table
____________________ ____
03-Jan-2018 12:28:00 87.2
03-Jan-2018 12:30:00 81
03-Jan-2018 12:32:00 75.3
03-Jan-2018 12:34:00 77.9
03-Jan-2018 12:36:00 83.2
03-Jan-2018 12:38:00 82.1
03-Jan-2018 12:40:00 82
03-Jan-2018 12:42:00 77.2

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