Table referencing using cell

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david crowley
david crowley 2023-1-6
回答： Stephen23 2023-1-6
Hi all,
I have two tables:
Tickers
Tickers nbr
________ ___
{'A2M' } 1
{'AAN' } 2
{'AAP' } 3
{'ABB' } 4
{'ABC' } 5
{'ABS' } 6
{'ADP' } 7
{'AEO' } 8
{'AFG1'} 9
{'AGL' } 10
Data
Date Code Open High Low Close Volume
___________ _______ _____ _____ _____ _____ ________
31-Mar-2015 {'A2M'} 0.555 0.595 0.53 0.565 4.816294
01-Apr-2015 {'A2M'} 0.575 0.58 0.555 0.565 4.37666
02-Apr-2015 {'A2M'} 0.56 0.565 0.535 0.555 2.77964
07-Apr-2015 {'A2M'} 0.545 0.55 0.54 0.545 0.392179
08-Apr-2015 {'A2M'} 0.545 0.545 0.53 0.54 0.668446
09-Apr-2015 {'A2M'} 0.54 0.54 0.532 0.535 0.706846
10-Apr-2015 {'A2M'} 0.53 0.535 0.53 0.535 0.175104
13-Apr-2015 {'A2M'} 0.535 0.54 0.53 0.54 0.565808
14-Apr-2015 {'A2M'} 0.54 0.54 0.535 0.54 0.371393
15-Apr-2015 {'A2M'} 0.54 0.55 0.54 0.54 0.925749
I need to create a new column in data called 'CodeRef' that brings the nbr column from the Tickers table into the corresponding code in the data table.
I've tried find, ismember - but for some reason I am missing something.

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采纳的回答

Voss
Voss 2023-1-6
编辑：Voss 2023-1-6
Ran in:
% some (simplified) tables like yours:
data = table({'a';'b';'c';'c';'a';'b';'b'}, ...
[3;4;6;8;3;5;4],'VariableNames',{'Code','Open'})
data = 7×2 table
Code Open _____ ____ {'a'} 3 {'b'} 4 {'c'} 6 {'c'} 8 {'a'} 3 {'b'} 5 {'b'} 4
Tickers = table({'a';'b';'c'},[1;2;3],'VariableNames',{'Tickers','nbr'})
Tickers = 3×2 table
Tickers nbr _______ ___ {'a'} 1 {'b'} 2 {'c'} 3
[ism,idx] = ismember(data.Code,Tickers.Tickers);
data.CodeRef = NaN(size(data,1),1); % in case any data.Code is missing from Tickers.Tickers, its CodeRef will be NaN
data.CodeRef(ism) = Tickers.nbr(idx(ism))
data = 7×3 table
Code Open CodeRef _____ ____ _______ {'a'} 3 1 {'b'} 4 2 {'c'} 6 3 {'c'} 8 3 {'a'} 3 1 {'b'} 5 2 {'b'} 4 2

更多回答（1 个）

Stephen23
Stephen23 2023-1-6
Ran in:
The simple MATLAB approach is to use the JOIN() family:
data = table({'a';'b';'c';'c';'a';'b';'b'}, [3;4;6;8;3;5;4],'VariableNames',{'Code','Open'})
data = 7×2 table
Code Open _____ ____ {'a'} 3 {'b'} 4 {'c'} 6 {'c'} 8 {'a'} 3 {'b'} 5 {'b'} 4
Tickers = table({'a';'b';'c'},[1;2;3],'VariableNames',{'Tickers','nbr'})
Tickers = 3×2 table
Tickers nbr _______ ___ {'a'} 1 {'b'} 2 {'c'} 3
out = join(data,renamevars(Tickers,'Tickers','Code'))
out = 7×3 table
Code Open nbr _____ ____ ___ {'a'} 3 1 {'b'} 4 2 {'c'} 6 3 {'c'} 8 3 {'a'} 3 1 {'b'} 5 2 {'b'} 4 2

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