Importing data from specific columns of a data structure

Hello all,

I am working on a large data file and want to extract the data for specific dates. The format of the file resembles the following:

Date Location Degree1 Degree2

20200101 NY 0 1

20200102 NY 0 0

20200103 NY 1 3

Now what if I want to extract all the data from 20200101 to 20200103?

Answer 1

[Voss]

T = readtable('data.txt')

T = 6×4 table
      Date      Location    Degree1    Degree2
    ________    ________    _______    _______

    2.02e+07     {'NY'}        0          1   
    2.02e+07     {'NY'}        0          0   
    2.02e+07     {'NY'}        1          3   
    2.02e+07     {'NY'}        1          9   
    2.02e+07     {'NY'}        2          7   
    2.02e+07     {'NY'}        2          6   

T(T.Date >= 20200101 & T.Date <= 20200103,:)

ans = 3×4 table
      Date      Location    Degree1    Degree2
    ________    ________    _______    _______

    2.02e+07     {'NY'}        0          1   
    2.02e+07     {'NY'}        0          0   
    2.02e+07     {'NY'}        1          3   

[Voss]

It may be convenient to work with datetime dates

T = readtable('data.txt');
T.Date = datetime(T.Date,'ConvertFrom','yyyymmdd')

T = 6×4 table
       Date        Location    Degree1    Degree2
    ___________    ________    _______    _______

    01-Jan-2020     {'NY'}        0          1   
    02-Jan-2020     {'NY'}        0          0   
    03-Jan-2020     {'NY'}        1          3   
    04-Jan-2020     {'NY'}        1          9   
    05-Jan-2020     {'NY'}        2          7   
    06-Jan-2020     {'NY'}        2          6   

T(T.Date >= '01-Jan-2020' & T.Date <= '03-Jan-2020',:)

ans = 3×4 table
       Date        Location    Degree1    Degree2
    ___________    ________    _______    _______

    01-Jan-2020     {'NY'}        0          1   
    02-Jan-2020     {'NY'}        0          0   
    03-Jan-2020     {'NY'}        1          3   

T(T.Date >= '2020-01-01' & T.Date <= '2020-01-03',:)

ans = 3×4 table
       Date        Location    Degree1    Degree2
    ___________    ________    _______    _______

    01-Jan-2020     {'NY'}        0          1   
    02-Jan-2020     {'NY'}        0          0   
    03-Jan-2020     {'NY'}        1          3   

T(T.Date >= 'Jan 01, 2020' & T.Date <= 'Jan 03, 2020',:)

ans = 3×4 table
       Date        Location    Degree1    Degree2
    ___________    ________    _______    _______

    01-Jan-2020     {'NY'}        0          1   
    02-Jan-2020     {'NY'}        0          0   
    03-Jan-2020     {'NY'}        1          3   

[Shirin]

This helps a lot; thank you so much.

[Voss]

You're welcome!