Adding a new column in table based on matching number from other columns in the same table

Hi,

I am trying to create an additional column of 'choice', which should contain either 'air,'trian','bus', 'car' depending upon where 1 has appeared in their respective column for given row.

I am unable to write the code that searches for 1 in columns in AIR, Train, Bus, Car and append the name of the column (e.g., car in first row) to new column named as 'choice'.

Any help would be highly appreciated.

Best wishes,

Answer 1

[nick]

Hi Yasir,

You can use logical indexing function to allocate the value in column 'choice'.

You can iterate over each row, check which column has the value 1, and then assign the corresponding column name to the new column 'choice'. Here's a MATLAB script that illustrates the same :

T = readtable('mode_choice');
options = {'AIR', 'Train', 'Bus', 'Car'};

% Preallocate the 'choice' column with empty strings
T.choice = strings(height(T), 1);

for i = 1:height(T)
    % Find the column with value 1
    idx = find([T.AIR(i), T.Train(i), T.Bus(i), T.Car(i)] == 1);
    
    % Check if any column contains 1
    if ~isempty(idx)
        T.choice(i) = options{idx};
    end
end

disp(T);

You can refer to the following documentation to learn more about 'logical indexing':

https://blogs.mathworks.com/loren/2013/02/20/logical-indexing-multiple-conditions/

[Yasir]

@nick, thanks for helping out. It worked and thanks for referring to logical indexing, which i was unable to handle.

Bundle of thanks again.