MATLAB: From discrete dates to continuous dates (revised)

MATLAB

I have a timetable T like
city date visitors
-----------------------
NY January 1 2020  100
NY January 5 2020   40
NY January 12 2020 300
SF January 1 2020  70
SF January 6 2020   240
SF January 15 2020 30
I want to embed this in a larger table with continuous dates such as
city date visitors
-----------------------
 NY January 1 2020  100
 NY January 2 2020  NaN
 NY January 3 2020  NaN
 NY January 4 2020  Nan
 NY January 5 2020   40
...
How can one do this?

Best Answer

Here's a sample timetable.
dt = datetime(2020, 1, [1; 5; 12]);
T = timetable(dt, [100; 40; 300], 'VariableNames', "visitors");
T.Properties.DimensionNames{1} = 'date'
T = 3x1 timetable
       date        visitors
    ___________    ________

    01-Jan-2020      100   
    05-Jan-2020       40   
    12-Jan-2020      300
retime it either filling rows not appearing in the original with missing (the default) or with the constant 0 
T_fillWithMissing = retime(T, 'daily')
T_fillWithMissing = 12x1 timetable
       date        visitors
    ___________    ________

    01-Jan-2020      100   
    02-Jan-2020      NaN   
    03-Jan-2020      NaN   
    04-Jan-2020      NaN   
    05-Jan-2020       40   
    06-Jan-2020      NaN   
    07-Jan-2020      NaN   
    08-Jan-2020      NaN   
    09-Jan-2020      NaN   
    10-Jan-2020      NaN   
    11-Jan-2020      NaN   
    12-Jan-2020      300   

T_fillWith0 = retime(T, 'daily', 'fillwithconstant', 'Constant',0)
T_fillWith0 = 12x1 timetable
       date        visitors
    ___________    ________

    01-Jan-2020      100   
    02-Jan-2020        0   
    03-Jan-2020        0   
    04-Jan-2020        0   
    05-Jan-2020       40   
    06-Jan-2020        0   
    07-Jan-2020        0   
    08-Jan-2020        0   
    09-Jan-2020        0   
    10-Jan-2020        0   
    11-Jan-2020        0   
    12-Jan-2020      300
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