User Defined Function to Add Fields to Table

Hi all, I am a matlab beginner and am trying to create a user defined function that will take the "Date" column of a table, split it into 3 new columns (Day/Month/Year), and add them to the input table. I do not know if this is possible as a function. Currently I have it set up as:

function [] = splitdate(x)

%Turns dates into a serial number

Date= datenum(x.Date);  

%Creates variable for Time stamps

Time= x.Time;

%Concatenates date and time entries into serial datetime numbers. 

DateTime= Date + Time;

%Add fields to table for Day/Month/Year

DateVec= datevec(DateTime); %takes serial date numbers and makes column vectors

x.Day = DateVec(:, 3);

x.Month = DateVec(:,2); 

x.Year = DateVec(:, 1);

It might be that I am trying to do too much with one function, but any feedback would be helpful. x would be whatever name was assigned for the table that was read in using readtable.

Thanks

[CS Researcher]

Can you give an example of the input x?

[Rachel McLaughlin]

The input x would be a table read in from an excel file using

filename= 'spreadsheet.xlsx'; Table= readtable(filename, 'Sheet', 1);

Answer 1

[Walter Roberson]

It is possible as a function. However, remember that most things are passed into functions by value, not by reference, so if you want to change something that is an input parameter, you need to return the new version of it from the function and the calling routine needs to assign it on top of the old variable.

   function x = splitdate(x)
     ...

with the caller doing

   MyTable = splitdate(MyTable);      %same name on input and output.

[Rachel McLaughlin]

Excellent! Thank you very much! I had figured it had something to do with my function output but wasn't sure how to make it work.