Why do I see an error when adding character data to a table?

I have a table like the following:

x=[1;2;3];
y=[4;5;6];
T=table(x,y)

Then I add a column of placeholder values:

z=zeros(3,1);
T=horzcat(T,table(z))

Now want to fill in the table with data from a serial port:

for i=1:3
    T{i,'z'} = query(device,'command')    % or: T(i,'z') = query(device,'command')
end

I get one of the following errors:

The value being assigned from must have 1 columns.

or

The number of table variables in an assignment must match.

How can I put this data in the table?

Answer 1

[MathWorks Support Team]

You are seeing these errors because the value returned from the query function is a 1xN character vector, but the data in that spot of the table is a 1x1 double. The data in a column must all have the same type and size.

Instead, make this a column of strings. You can still create placeholder values and fill them in one by one.

z=strings(3,1);
T=horzcat(T,table(z))
for i=1:3
    T{i,'z'} = string(query(device,'command'))
end