Reorder table variables / columns

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Alan
Alan on 18 Sep 2014
Commented: Justin Elstrott on 13 Jan 2021
I've created a table from a large csv file using the readtable function. I want to reorder the variables / columns in this table.
For example.
My table's name is CUTable
It has a variable CUTable.Date which is the date the data was taken It is currently column 20 in the table. I want to make it column 2 and shift existing columns 2-19 to 3-20.
It seems there should be a very easy command to do this which I'm missing, but I can't seem to find it anywhere in the help or these forums. I could, but don't want to "brute force" it (e.g. create a new table, and one-by-one copy the variables from the exiting table to the new table in the order I want, then delete the old table) if avoidable.
How can I accomplish this?

Accepted Answer

Geoff Hayes
Geoff Hayes on 18 Sep 2014
Edited: Geoff Hayes on 18 Sep 2014
Alan - you can try the following to move the 20th column to the second position
CUTable = [CUTable(:,1) CUTable(:,20) CUTable(:,2:19)];
It isn't as elegant as a simple "move column command" but it should do what you want. In the following example, I inserted the last column in before the second (note that I use end here rather than the last column number)
load patients;
T = table(Age,Diastolic,Gender,Height,LastName,Location,...
SelfAssessedHealthStatus,Smoker,Systolic,Weight)
T = [T(:,1) T(:,end) T(:,2:end-1)]
  3 Comments
Peter Perkins
Peter Perkins on 21 Feb 2018
Yes, for a simple rearrangement, what Ole suggests is the best way. In some cases, it will be more readable use variable names, something such as
T = array2table(rand(10,3),'VariableNames',{'x' 'y' 'z'})
T = T(:,{'z' 'y' 'x'})
but with more than a handful of variables, probably using numbers is more readable.

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More Answers (2)

Eric Sofen
Eric Sofen on 28 Mar 2018
In R2018a, check out the new movevars function for rearranging variables in tables. It's part of a set of new functions for manipulating table variables:

Ben Oeveren
Ben Oeveren on 21 Feb 2018
Edited: Ben Oeveren on 21 Feb 2018
Or you can use:
oldvariables = T.Properties.VariableNames;
newvariables = {'date','Title','Website'};
[~,LOCB] = ismember(oldvariables,newvariables);
newTable = T(:,LOCB);
  1 Comment
Justin Elstrott
Justin Elstrott on 13 Jan 2021
Hi Ben,
I like this solution, but there's a typo in the third line. I believe it should read as:
oldvariables = T.Properties.VariableNames;
newvariables = {'date','Title','Website'};
[~,LOCB] = ismember(newvariables,oldvariables);
newTable = T(:,LOCB);

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