MATLAB: How to select multiple columns in a table using variable names and wildcards

tables indexing wildcard

Hi all,
I am trying to index and extract a series of variables from a table i've created based on the VariableNames. I would rather index using the VariableNames as opposed to numerical or logical index due to the fact that there might be different numbers of trials for the variables.
Using the below code I can call one variable at a time. The '_1' represents the trial number which could go up to '_20'.
C1vC2Trials = C1MPVNormVariables(:,'C1MPVNorm_1');
However when trying to use the * wildcard to call all trials for that variable I get an error.
Error: Unrecognized variable name 'C1MPVNorm_*'.
Is this possible to do with tables or is there a easy work around to find the number of VariableNames in the table which correspond to the ones I wish to extract?
Thanks in advance!

Best Answer

I am not using tables, so you should probably wait for a better answer, but here is one way that I could see. Say we have the table:
 T =
  5×4 table
                Age    Height    Weight    BloodPressure
                ___    ______    ______    _____________
    Smith       38     71        176       124     93   
    Johnson     43     69        163       109     77   
    Williams    38     64        131       125     83   
    Jones       40     67        133       117     75   
    Brown       49     64        119       122     80
and we want all variables that contain the string 'ei' (pattern):
 >> hasMatch = ~cellfun('isempty', regexp(T.Properties.VariableNames, 'ei', 'once')) ;
 >> T(:, T.Properties.VariableNames(hasMatch))
 ans =
  5×2 table
                Height    Weight
                ______    ______
    Smith       71        176   
    Johnson     69        163   
    Williams    64        131   
    Jones       67        133   
    Brown       64        119
Here we are using regular expressions, so you must use regexp types of "wildcards".
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