ExprAggrNodeArray.h

Go to the documentation of this file.

// # ExprAggrNodeArray.h: TaQL node representing an array aggregate function
// # Copyright (C) 2013
// # Associated Universities, Inc. Washington DC, USA.
// #
// # This library is free software; you can redistribute it and/or modify it
// # under the terms of the GNU Library General Public License as published by
// # the Free Software Foundation; either version 2 of the License, or (at your
// # option) any later version.
// #
// # This library is distributed in the hope that it will be useful, but WITHOUT
// # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// # FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
// # License for more details.
// #
// # You should have received a copy of the GNU Library General Public License
// # along with this library; if not, write to the Free Software Foundation,
// # Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
// #
// # Correspondence concerning AIPS++ should be addressed as follows:
// #        Internet email: casa-feedback@nrao.edu.
// #        Postal address: AIPS++ Project Office
// #                        National Radio Astronomy Observatory
// #                        520 Edgemont Road
// #                        Charlottesville, VA 22903-2475 USA
 
#ifndef TABLES_EXPRAGGRNODEARRAY_H
#define TABLES_EXPRAGGRNODEARRAY_H
 
// # Includes
#include <casacore/casa/aips.h>
#include <casacore/tables/TaQL/ExprFuncNodeArray.h>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// # Forward Declarations.
class TableExprGroupFuncBase;
class TableExprGroupFuncSet;
 
// <summary>
// TaQL node representing an array aggregate function
// </summary>
 
// <use visibility=local>
 
// <reviewed reviewer="" date="" tests="tTaQLNode">
// </reviewed>
 
// <synopsis>
// This class is similar to TableExprAggrNode, but its result is an array
// instead of a scalar value.
// There are few aggregate functions resulting in an array. An example
// is <src>gaggr</src>, which aggregates the non-empty arrays in a group
// into a single array. Other functions (like medians, runningmean, etc.)
// can be applied to its result making it quite versatile.
//
// Most array aggregate functions are lazy to avoid using too much memory.
// </synopsis>
 
class TableExprAggrNodeArray : public TableExprFuncNodeArray {
 public:
  // Constructor.
  TableExprAggrNodeArray(TableExprFuncNode::FunctionType, NodeDataType, ValueType,
                         const TableExprNodeSet& source, const vector<TENShPtr>& nodes,
                         const Block<Int>& dtypeOper, const TaQLStyle& style);
 
  // This node does aggregation.
  virtual Bool isAggregate() const;
 
  // Get the operand node.
  TENShPtr operand() { return (operands().empty() ? TENShPtr() : operands()[0]); }
 
  // Create the correct aggregate function object.
  virtual std::shared_ptr<TableExprGroupFuncBase> makeGroupAggrFunc();
 
  // Is the array aggregate function lazy?
  virtual Bool isLazyAggregate() const;
 
  // Functions to get the result of an aggregate function.
  // <group>
  virtual MArray<Bool> getArrayBool(const TableExprId& id);
  virtual MArray<Int64> getArrayInt(const TableExprId& id);
  virtual MArray<Double> getArrayDouble(const TableExprId& id);
  virtual MArray<DComplex> getArrayDComplex(const TableExprId& id);
  virtual MArray<String> getArrayString(const TableExprId& id);
  virtual MArray<MVTime> getArrayDate(const TableExprId& id);
  // </group>
 
 private:
  // Create the correct aggregate function object.
  std::shared_ptr<TableExprGroupFuncBase> doMakeGroupAggrFunc();
 
  // # Data members.
  std::shared_ptr<TableExprGroupFuncBase> itsFunc;
};
 
}  // namespace casacore
 
#endif