MATLAB Answers

Adding time and date to table

26 views (last 30 days)
Hi i want to read a csv file and add in the first column from row 3 to end a date and time vector which i generate with the following code
ElmLnecloading = readtable('ElmLne_c_loading.csv');
t1 = datetime(2017,1,1,0,15,0);
t2 = datetime(2017,12,31,23,45,0);
interval = minutes(15);
Vector = (t1:interval:t2);
DateString = char(Vector');
disp(DateString)
ElmLnecloading(3:end,1) = DateString;
disp(ElmLnecloading)
but i always get the following error:
To assign to or create a variable in a table, the number of rows must match the height of the table.
A picture of a part of the file is attached. It has 35041 rows
Can someone help me how to solve the problem or having an easier way to solve my problem? I am pretty new to Matlab...
  1 Comment
Benedikt Skurk
Benedikt Skurk on 2 Mar 2021
Thanks for the help!! appreciate it !

Sign in to comment.

Accepted Answer

Cris LaPierre
Cris LaPierre on 2 Mar 2021
Edited: Cris LaPierre on 2 Mar 2021
In MATLAB, all elements of one table variable should be of the same data type. For this reason, I suspect your table in MATLAB has removed the first 2 rows. This means (3:end,1) is actually 2 rows shorter than DateString, resulting in the size mismatch error.
Tables allow you to have variables of different datatypes in the same table. I would therefore recommend keeping your dates as datetimes.
t1 = datetime(2017,1,1,0,15,0);
t2 = datetime(2017,12,31,23,45,0);
interval = minutes(15);
Vector = (t1:interval:t2)';
data = rand(length(Vector),1);
dTbl = table(Vector,data)
dTbl = 35039x2 table
Vector data ____________________ _______ 01-Jan-2017 00:15:00 0.13599 01-Jan-2017 00:30:00 0.90735 01-Jan-2017 00:45:00 0.9517 01-Jan-2017 01:00:00 0.63316 01-Jan-2017 01:15:00 0.40791 01-Jan-2017 01:30:00 0.31211 01-Jan-2017 01:45:00 0.97797 01-Jan-2017 02:00:00 0.46379 01-Jan-2017 02:15:00 0.28019 01-Jan-2017 02:30:00 0.10032 01-Jan-2017 02:45:00 0.51595 01-Jan-2017 03:00:00 0.64312 01-Jan-2017 03:15:00 0.87067 01-Jan-2017 03:30:00 0.98085 01-Jan-2017 03:45:00 0.61279 01-Jan-2017 04:00:00 0.65733
  1 Comment
Benedikt Skurk
Benedikt Skurk on 2 Mar 2021
Thanks for the help! appreciate it !

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!