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function subds = partition(ds, partitionStrategy, partitionIndex) %PARTITION Return a partitioned part of the TabularText Datastore. % % SUBDS = PARTITION(DS,NUMPARTITIONS,INDEX) partitions DS into % NUMPARTITIONS parts and returns the partitioned TabularTextDatastore, % SUBDS, corresponding to INDEX. An estimate for a reasonable value for the % NUMPARTITIONS input can be obtained by using the NUMPARTITIONS function. % % SUBDS = PARTITION(DS,'Files',INDEX) partitions DS by files in the % Files property and returns the partition corresponding to INDEX. % % SUBDS = PARTITION(DS,'Files',FILENAME) partitions DS by files and % returns the partition corresponding to FILENAME. % % Example: % % A datastore that contains 10 copies of the 'airlinesmall.csv' % % example dataset. % files = repmat({'airlinesmall.csv'},1,10); % ds = tabularTextDatastore(files,'TreatAsMissing','NA','MissingValue',0); % ds.SelectedVariableNames = 'ArrDelay'; % % % This will parse approximately the first third of the example data. % subds = partition(ds,3,1); % % totalSum = 0; % while hasdata(subds) % data = read(subds); % totalSum = totalSum + sum(data.ArrDelay); % end % totalSum % % See also matlab.io.datastore.TabularTextDatastore, numpartitions. % Copyright 2014 The MathWorks, Inc. try subds = partition@matlab.io.datastore.FileBasedDatastore(ds, partitionStrategy, partitionIndex); catch e throw(e) end end