Reassign Categorical Variable Value

Hello everyone,

I built a 7647×2 Table with Variables "td" for Trading week-day and "close" for the closing prices of the Swiss Market Index, where td is Categorical and close Double

The Market is open only from Monday to Friday, but the td variable summary displays some "Sunday" observation. I checked on the Calendar and those are actually either Mondays or Fridays.

Is there I way I can replace all Sundays with the appropriate Day? I tried with the following:

for i = 1:length(td);
    for td(i) == 'Sunday'; %for all Sundays in the Sample
        if td(i+1) == 'Monday'
            td(i) == 'Friday' %change to friday if the following day is monday
        elseif td(i+1) == 'Tuesday'
            td(i) == 'Monday' %change to monday if the following day is tuesday
        end
    end;
end;

But I am a mess with for loops and if statements and I am not really sure how to use them with categorical variables

Anyone could help?

Answer 1

[Peter Perkins]

If you wanted to all the sundays into mondays, it would be easy: combinecats. But you want to turn them into either mondays or fridays depending on whether they are followed by a monday or a tuesday. Right?

You should be able to do this without loops:

i1 = (t.td(1:end-1) == 'Sunday') && (t.td(2:end) == 'Monday');
t.td(i1) = 'Friday';
i2 = (t.td(1:end-1) == 'Sunday') && (t.td(2:end) == 'Tuesday');
t.td(i2) = 'Monday';
t.td = removecats(t.td); % drop the now unused Sunday