Class StepDataStore

java.lang.Object
uk.ac.starlink.ttools.plot2.data.StepDataStore
All Implemented Interfaces:
DataStore

public class StepDataStore extends Object implements DataStore
Wrapper data store implementation that dispenses all column data as evenly spaced subsamples by row.
Since:
13 Nov 2013
Author:
Mark Taylor
  • Constructor Details

    • StepDataStore

      public StepDataStore(DataStore base, int step)
      Constructor.
      Parameters:
      base - base data store to which most behaviour is delegated
      step - stride indicating the size of the subsample; step=1 means all rows, step=2 means every other one etc
  • Method Details

    • getTupleSequence

      public TupleSequence getTupleSequence(DataSpec spec)
      Description copied from interface: DataStore
      Returns the data described by a given DataSpec as a sequence of tuples. Must only be called if DataStore.hasData(uk.ac.starlink.ttools.plot2.data.DataSpec) returns true for the given DataSpec; if not, behaviour is undefined.
      Specified by:
      getTupleSequence in interface DataStore
      Parameters:
      spec - plot data specification object
      Returns:
      sequence of values which can be used to perform a plot
    • hasData

      public boolean hasData(DataSpec spec)
      Description copied from interface: DataStore
      Indicates whether this store has the data described by a given DataSpec.
      Specified by:
      hasData in interface DataStore
      Parameters:
      spec - plot data specification object
    • getTupleRunner

      public TupleRunner getTupleRunner()
      Description copied from interface: DataStore
      Returns an object that manages iteration over tuples. Where possible, the returned TupleRunner should be used for iteration when using this DataStore, since it contains the chosen policy for parallel execution. If only sequential processing is supported however, TupleSequences acquired from this store can be used directly.
      Specified by:
      getTupleRunner in interface DataStore
      Returns:
      tuple runner