User Defined Function to Add Fields to Table

Question

Rachel McLaughlin 2016-5-3

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/282239-user-defined-function-to-add-fields-to-table

评论： Rachel McLaughlin 2016-5-4

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

2 个评论
显示无隐藏无

CS Researcher 2016-5-3

Can you give an example of the input x?

Rachel McLaughlin 2016-5-4

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

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

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Walter Roberson 2016-5-3

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/282239-user-defined-function-to-add-fields-to-table#answer_220498

在 MATLAB Online 中打开

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.