Find min and max datetime in table

Question

Frederick Awuah-Gyasi 2022-5-19

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1723330-find-min-and-max-datetime-in-table

评论： Voss 2022-5-19

采纳的回答： Voss

table

A , Datetime,

2 05/20/22

2 05/20/23

3 04/12/99

3 06/12/02

the goal is to have two more columns with min and max dates

table

A , Datetime, Min, Max

2 05/2/22 05/2/22 05/2/23

2 05/2/23 05/2/22 05/2/23

3 04/12/01 04/12/01 06/12/02

3 06/12/02 04/12/01 06/12/02

I was tring table_min = groupsummary (table,{table.A,table.Datetime}, 'min'}

table_max= groupsummary (table,{table.A,table.Datetime}, 'max'}

So I join this date to table but i'm getting an error :

[groupingData,groupVars] = matlab.internal.math.parseGroupVars(groupVars,tableFlag,'groupsummary',T);

Thank you.

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Answer 1

Voss 2022-5-19

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1723330-find-min-and-max-datetime-in-table#answer_967730

在 MATLAB Online 中打开

T = table( ...
    [2;2;3;3], ...
    datetime({'05/20/22';'05/20/23';'04/12/99';'06/12/02'},'InputFormat','MM/dd/yy'), ...
    'VariableNames',{'A' 'Datetime'})
T = 4×2 table
    A     Datetime  
    _    ___________

    2    20-May-2022
    2    20-May-2023
    3    12-Apr-1999
    3    12-Jun-2002
table_min = groupsummary (T, 'A', 'min')
table_min = 2×3 table
    A    GroupCount    min_Datetime
    _    __________    ____________

    2        2         20-May-2022 
    3        2         12-Apr-1999 
table_max = groupsummary (T, 'A', 'max')
table_max = 2×3 table
    A    GroupCount    max_Datetime
    _    __________    ____________

    2        2         20-May-2023 
    3        2         12-Jun-2002 
g = findgroups(T.A)
g = 4×1
     1
     1
     2
     2
T.Min = table_min{g,'min_Datetime'};
T.Max = table_max{g,'max_Datetime'};
T
T = 4×4 table
    A     Datetime          Min            Max    
    _    ___________    ___________    ___________

    2    20-May-2022    20-May-2022    20-May-2023
    2    20-May-2023    20-May-2022    20-May-2023
    3    12-Apr-1999    12-Apr-1999    12-Jun-2002
    3    12-Jun-2002    12-Apr-1999    12-Jun-2002