MATLAB: Separating Data into columns based on certain text variable in that data

parsingseparation

I have a list of daily stock returns for each stock on the S&P 500. The returns are formatted so that each stock is grouped together like this:
1/1/2013 AAPL .005%
1/2/2013 AAPL -.1%
….
1/1/2013 GOOG .5%
1/2/2013 GOOG .25%
How would I sort this so that the each stock can be a column name and have its returns below it?
Thanks!

Best Answer

>> data=readtable('jack.dat','format','%{MM/dd/yyyy}D %s %f%%')
data = 
     Var1        Var2     Var3 
  __________    ______    _____
  01/01/2013    'AAPL'    0.005
  01/02/2013    'AAPL'     -0.1
  01/01/2013    'GOOG'      0.5
  01/02/2013    'GOOG'     0.25
>> [u,~,ic]=unique(data.Var2);
>> stks=table(data.Var1(ic==1));   % get the dates first; must all be same
>> for i=1:length(u)               % get each individual stock
     stks(:,i+1)=table(data.Var3(ic==i));end
>> stks.Properties.VariableNames=[{'Date'}, u.']  % add useful names
stks = 
     Date       AAPL     GOOG
  __________    _____    ____
  01/01/2013    0.005     0.5
  01/02/2013     -0.1    0.25
>> clear data                      % done with it...
Above does assume that every stock has the identical timestamp; any missing will cause failure.
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