Add a variable to table

Hi,

I want to join 2 tables together.

In order to do that, table 1 must have the same number of columns as table 2.

table 1 has 8 variables

table 2 has 9 variables

So, I want to add a column to table 8

The variable will be of no use - it will just be a kind of dummy variable

How can I do this?

Thank you.

Answer 1

[Turlough Hughes]

Hey Sarah,

Let's say you have two tables, as follows:

T1=table((1:10).',(10:-1:1).');
T2=table((11:20).',(20:-1:11).',(1:10).');

To add a dummy column you could write the following;

T1.dummy=NaN(size(T1,1),1);

To concatenate them, ensure firstly that the VariableNames are the same, which ought to be the case anyway except for T1.dummy:

T1.Properties.VariableNames=T2.Properties.VariableNames;

You can then concatenate the tables as follows:

T=[T1;T2];

Finally, with this approach I assume that the values in the last column of T2 are still important (otherwise you could just write a table without the last column of T1)

T=[T1;T2(:,1:end-1)];

EDIT: following comments below.

[Sarah Yun]

Hi, thanks.

I want to concatenate them vertically.

[Turlough Hughes]

Ah ok. Do the variables have the same names?

[Turlough Hughes]

For example if you had:

T1=table((1:10).',(10:-1:1).');
T2=table((11:20).',(20:-1:11).',(1:10).');

You could concatenate them as follows:

T=[T1; T2(:,1:end-1)];

[Turlough Hughes]

Did this work for you?