MATLAB: Error using Unique for table to remove duplicate rows which consists of mixed data types

MATLABtableunique

Dear Experts,
I have a table with mixed data types. I try to remove duplicate rows according to column 1 (string) and column 2 (integer).
ie Inputs: Table X:
Ticker  Date Price
AAPL   20160201 100
IBM    20160202 20.1
AAPL   20160202 90
AAPL   20160201 200
Desired output
Ticker  Date Price
AAPL   20160201 200
AAPL   20160202 90
IBM    20160202 20.1
My code
[~,b] = unique(X(:,[1 2]), 'rows');
tmp = X(b,:);
but I have this error.
Error using cell/unique (line 85) Input A must be a cell array of strings.
Error in pre_process (line 12)
Thanks

Best Answer

Is your table really a table? Or is it a cell array? The error you're getting implies the latter. As the error message implies, the unique function only works on cell arrays of strings, not of mixed data types. But the table method unique should work fine:
tmp = {...
'Ticker'  'Date' 'Price'
'AAPL'   20160201 100
'IBM'    20160202 20.1
'AAPL'   20160202 90
'AAPL'   20160201 200}
unique(tmp(2:end,:);, 'rows');
Result:
Error using cell/unique (line 85)
Input A must be a cell array of strings.
But:
tbl = cell2table(tmp(2:end,:), 'variablenames', tmp(1,:));
[a,b] = unique(tbl(:,1:2), 'rows')
a = 
      Ticker      Date   
      ______    _________
      'AAPL'    2.016e+07
      'AAPL'    2.016e+07
      'IBM'     2.016e+07
b =
       1
       3
       2
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