How do I add a column to table?

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I have created a CSV file. When I use the "readable" function to load the table, I get an 8x10 table. I want to expand the table to an 8x11 table, where the 11th column should have the values from a function I have created. How do I do this?

Accepted Answer

Walter Roberson
Walter Roberson on 15 May 2024
Edited: MathWorks Support Team on 5 Jun 2024
You can add a new table variable by using either dot notation or the "addvars" function. Dot notation adds new variables to the end of table. If you use the "addvars" function, then you can choose the location of the new table variable. 
For example, this code creates a table and two column vectors. Then it adds the column vectors to the table as new variables.
LastName = ["Sanchez";"Johnson";"Li";"Diaz";"Brown"];
Age = [38;43;38;40;49];
Smoker = logical([1;0;1;0;1]);
T = table(LastName,Age,Smoker);
T.NewData = rand(5,1) % Dot notation adds new variable to end of table
MoreData = rand(5,1);
T = addvars(T,MoreData,'Before',1) % Add variable to beginning of table
If you generate a table variable name by evaluating an expression, you can pass it as the name of the new variable with either of these syntaxes. 
TodaysData = "Data " + string(datetime("today"));
T.(TodaysData) = rand(5,1)
YesterdaysData = "Data " + string(datetime("today") - 1);
T = addvars(T,rand(5,1),'NewVariableNames',YesterdaysData,'Before',1)
For more information, see the following documentation:
Add, Delete, and Rearrange Table Variables
https://www.mathworks.com/help/matlab/matlab_prog/add-and-delete-table-variables.html

More Answers (3)

Sean de Wolski
Sean de Wolski on 20 Nov 2015
T.EleventhColumn = rand(8,1);
Where 'EleventhColumn' is the name you want for the variable.
  2 Comments
Yifei
Yifei on 26 Nov 2022
The most convenient approach.

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thang ngo
thang ngo on 24 Jul 2020
This helps to pass a name as parameter:
name = 'new_column'
T.(name) = rand(8,1);

Ehab Abdelkarim
Ehab Abdelkarim on 3 Aug 2018
you may want to check the following link https://de.mathworks.com/help/matlab/matlab_prog/add-and-delete-table-variables.html

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