MATLAB: Introduce columns in a table- Variables

table

Hi, I want to introduce columns in a table, then I write Table.a but a is a variable string and I want that the column has the name of this string how I can do that???

Best Answer

This is possible using a slight variation of the cyclist's initial approach.

% Sample data
A = magic(4);
% Create the table to which you want to add data
T = array2table(A, 'VariableNames', {'first', 'second', 'third', 'fourth'})
% Define the new variable and the data it should contain
newvariable = 'fifth';
x = [20; 17; 8; 2];
% Add the new variable to the table T
T.(newvariable) = x

Related Solutions

MATLAB: Add a variable to a table

If your table is named T, and your workspace variable is named k, and you want the new variable in the table to be named k, then it's just

T.k = k

MATLAB: Existing table, populate a column with string (receiving errors)

You are close, but you are trying to assign a character vector to a double variable (NaN = not a number). You can see that if you run the command summary(mytable).

You also do not need to put the text into a cell if you use the string data type.

See if you can get this code to work for your needs.

myArray = nan(5,2)
mytable = array2table(myArray);
mytable.Properties.VariableNames = {'colA', 'colB'};
mytable2 = convertvars(mytable,"colB",'string');
mytable2.colA(:) = 459;
mytable2.colB(:) = "words"

You say you have a lot of data. If the variables already exist, you could do something like this:

colA = nan(5,1);
colB = strings(5,1);
mytable = table(colA,colB);
mytable.colA(:) = 459; % just a random number, proof-of-concept that it works
mytable.colB(:) = "words" % this throws errors

Best Answer

Related Solutions

MATLAB: Add a variable to a table

MATLAB: Existing table, populate a column with string (receiving errors)

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