MATLAB: Rehsaping Data Table to new format

tables

Hi, I have a data table that exists like:
[date] [field] [data]
1/1/2017 A 1
1/2/2017 A 2
1/3/2017 A 3
1/1/2017 B 3
1/2/2017 B 2
1/3/2017 B 1
1/1/2017 C 4
1/2/2017 C 5
1/3/2017 C 6
and i want to reshape the data to be like this:
[Date] [A] [B] [C]
1/1/2017 1 3 4
1/2/2017 2 2 5
1/3/2017 3 1 6
so that each unique value in fields becomes a new field name in the new table.
I saw this conversion done in a tutorial the other day, but cant recall how it was done at all, thanks for any input in advance!
Matt

Best Answer

I think you are looking for unstack:
>> t = cell2table( ...
    {'1/1/2017', 'A', 1; ...
     '1/2/2017', 'A', 2; ...
     '1/3/2017', 'A', 3; ...
     '1/1/2017', 'B', 3; ...
     '1/2/2017', 'B', 2; ...
     '1/3/2017', 'B', 1; ...
     '1/1/2017', 'C', 4; ...
     '1/2/2017', 'C', 5; ...
     '1/3/2017', 'C', 6},'VariableNames',{'date' 'field' 'data'});
>> t.date = datetime(t.date,'InputFormat','MM/dd/yyy');
>> t.field = categorical(t.field)
t =
  9×3 table
       date        field    data
    ___________    _____    ____
    01-Jan-2017      A       1  
    02-Jan-2017      A       2  
    03-Jan-2017      A       3  
    01-Jan-2017      B       3  
    02-Jan-2017      B       2  
    03-Jan-2017      B       1  
    01-Jan-2017      C       4  
    02-Jan-2017      C       5  
    03-Jan-2017      C       6  
>> t2 = unstack(t,'data','field')
t2 =
  3×4 table
       date        A    B    C
    ___________    _    _    _
    01-Jan-2017    1    3    4
    02-Jan-2017    2    2    5
    03-Jan-2017    3    1    6
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