How to combine 2 tables with different variables into 1 table?
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I would like to combine Table1 and Table2 into Table3 as shown below. Any advice on how it can be done?
I have used the below commands, but not successful.
Method 1
Table3 = join(Table1,Table2,'Keys','SysTime')
The above is not successful as the key variable for B must contain all values in the key variable for A.
Method 2
Table3 = [Table1 Table2]
The above is not successful due to the duplicate name 'SysTime'.
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/744739/image.jpeg)
2 个评论
Stephen23
2021-9-21
编辑:Stephen23
2021-9-21
To anyone reading this in the future: this is very simple to do with just one command.
Doing this by converting the tables to numeric matrix, sorting, identifying the matching elements via ISMEMBER and then creating a new table... is indirect, complex, obfuscated, and inefficient. Much better is to read the MATLAB documentation:
and read about the functions listed in the section "Join and Set Operations".
采纳的回答
KSSV
2021-9-21
Convert both the tables into arrays using table2array. And then you need to use below:
T1 = [1 2 3 4 5; 10 20 30 40 50]' ;
T2 = [1 1.5 2 2.5 3 ; 2 4 5 6 7]' ;
SysTime = [T1(:,1) ; T2(:,1)] ;
EDF1 = T1(:,2) ;
MDF2 = T2(:,2) ;
[SysTime,idx] = sort(unique(SysTime)) ;
EDF = NaN(size(SysTime)) ;
MDF = NaN(size(SysTime)) ;
[c,ia] = ismember(T1(:,1),SysTime) ;
EDF(ia) = EDF1 ;
[c,ia] = ismember(T2(:,1),SysTime) ;
MDF(ia) = MDF2 ;
T = table(SysTime,EDF,MDF)
更多回答(2 个)
Stephen23
2021-9-21
编辑:Stephen23
2021-9-21
The actual MATLAB solution just takes one simple line of code:
SysTime = [1;2;3;4;5];
EDF = [10;20;30;40;50];
T1 = table(SysTime,EDF)
SysTime = [1;1.5;2;2.5;5];
MDF = [2;4;5;6;7];
T2 = table(SysTime,MDF)
T3 = outerjoin(T1,T2, 'MergeKeys',true) % this is all you need.
3 个评论
Sulaymon Eshkabilov
2021-9-21
Note that join() works very well, but you should correctly define the two table to be joined. See this example:
A = (1:5)'; B = A*10; C = A+B; D = C/2; Item = (1:5)';
ABC = [Item, A, B]; CBD = [Item, C, D];
T1 = array2table(ABC, 'VariableNames', {'Item', 'A', 'B'});
T2 = array2table(CBD, 'VariableNames', {'Item', 'C', 'D'});
TT = join(T1, T2)
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