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function subds = partition(ds, partitionStrategy, partitionIndex) %PARTITION Return a partitioned part of the SpreadsheetDatastore. % % SUBDS = PARTITION(DS,NUMPARTITIONS,INDEX) partitions DS into % NUMPARTITIONS parts and returns the partitioned SpreadsheetDatastore, % 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.xlsx' % % example dataset. % ssds = spreadsheetDatastore(repmat({'airlinesmall_subset.xlsx'},1,10)); % ssds.SelectedVariableNames = 'ArrDelay'; % % % This will parse approximately the first third of the example data. % subds = partition(ssds,3,1); % % Sum the Arrival Delays % sumAD = 0; % % while hasdata(subds) % tab = read(subds); % data = tab.ArrDelay(~isnan(tab.ArrDelay)); % filter data % sumAD = sumAD + sum(data); % end % sumAD % % See also matlab.io.datastore.SpreadsheetDatastore, numpartitions. % Copyright 2015 The MathWorks, Inc. try subds = partition@matlab.io.datastore.FileBasedDatastore(ds, partitionStrategy, partitionIndex); catch ME throw(ME); end end