org.apache.sysds.lops

## Class PartialAggregate

- java.lang.Object
- - org.apache.sysds.lops.Lop
  - - org.apache.sysds.lops.PartialAggregate

-     public class PartialAggregate
      extends Lop

  Lop to perform a partial aggregation. It was introduced to do some initial aggregation operations on blocks in the mapper/reducer.

- - ### Nested Class Summary

    - ### Nested classes/interfaces inherited from class org.apache.sysds.lops.Lop

      `Lop.SimpleInstType, Lop.Type, Lop.VisitStatus`

  - ### Field Summary

    - ### Fields inherited from class org.apache.sysds.lops.Lop

      `_beginColumn, _beginLine, _endColumn, _endLine, _filename, CP_CHILD_THREAD, CP_ROOT_THREAD_ID, DATATYPE_PREFIX, FILE_SEPARATOR, FRAME_VAR_NAME_PREFIX, INSTRUCTION_DELIMITOR, LITERAL_PREFIX, MATRIX_VAR_NAME_PREFIX, NAME_VALUE_SEPARATOR, OPERAND_DELIMITOR, PROCESS_PREFIX, SAMPLE_FRACTION, SCALAR_VAR_NAME_PREFIX, UPDATE_INPLACE_PREFIX, VALUETYPE_PREFIX, VARIABLE_NAME_PLACEHOLDER`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `PartialAggregate(Lop input, Types.AggOp op, Types.Direction direct, Types.DataType dt, Types.ValueType vt, AggBinaryOp.SparkAggType aggtype, LopProperties.ExecType et)`
    `PartialAggregate(Lop input, Types.AggOp op, Types.Direction direct, Types.DataType dt, Types.ValueType vt, LopProperties.ExecType et, int k)`

  - ### Method Summary

    All Methods Static Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `Types.CorrectionLocationType` | `getCorrectionLocation()` This method computes the location of "correction" terms in the output produced by PartialAgg instruction.
    `static Types.CorrectionLocationType` | `getCorrectionLocation(Types.AggOp operation, Types.Direction direction)`
    `String` | `getInstructions(String input1, String output)` Instruction generation for for CP and Spark
    `static String` | `getOpcode(Types.AggOp op, Types.Direction dir)`
    `void` | `setDimensionsBasedOnDirection(long dim1, long dim2, long blen)`
    `static void` | `setDimensionsBasedOnDirection(Lop lop, long dim1, long dim2, long blen, Types.Direction dir)`
    `String` | `toString()` Method to have Lops print their state.

    - ### Methods inherited from class org.apache.sysds.lops.Lop

      `addInput, addOutput, addToDag, createReachable, getBeginColumn, getBeginLine, getDataType, getEndColumn, getEndLine, getExecType, getFilename, getID, getInputs, getInstructions, getInstructions, getInstructions, getInstructions, getInstructions, getInstructions, getInstructions, getInstructions, getInstructions, getInstructions, getInstructions, getLevel, getOutputParameters, getOutputs, getPrivacyConstraint, getProducesIntermediateOutput, getReachable, getSimpleInstructionType, getType, getValueType, getVisited, isDataExecLocation, isVariable, prepInputOperand, prepInputOperand, prepOperand, prepOperand, prepOutputOperand, prepOutputOperand, prepOutputOperand, prepScalarInputOperand, prepScalarInputOperand, prepScalarLabel, prepScalarOperand, printErrorLocation, removeConsumer, resetVisitStatus, setAllPositions, setBeginColumn, setBeginLine, setConsumerCount, setDataType, setEndColumn, setEndLine, setFilename, setPrivacyConstraint, setValueType, setVisited`

    - ### Methods inherited from class java.lang.Object

      `equals, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- - ### Constructor Detail

    - #### PartialAggregate

          public PartialAggregate(Lop input,
                                  Types.AggOp op,
                                  Types.Direction direct,
                                  Types.DataType dt,
                                  Types.ValueType vt,
                                  LopProperties.ExecType et,
                                  int k)

    - #### PartialAggregate

          public PartialAggregate(Lop input,
                                  Types.AggOp op,
                                  Types.Direction direct,
                                  Types.DataType dt,
                                  Types.ValueType vt,
                                  AggBinaryOp.SparkAggType aggtype,
                                  LopProperties.ExecType et)

  - ### Method Detail

    - #### getCorrectionLocation

          public Types.CorrectionLocationType getCorrectionLocation()

      This method computes the location of "correction" terms in the output produced by PartialAgg instruction. When computing the stable sum, "correction" refers to the compensation as defined by the original Kahan algorithm. When computing the stable mean, "correction" refers to two extra values (the running mean, count) produced by each Mapper i.e., by each PartialAgg instruction. This method is invoked during hop-to-lop translation, while creating the corresponding Aggregate lop Computed information is encoded in the PartialAgg instruction so that the appropriate aggregate operator is used at runtime (see: dml.runtime.matrix.operator.AggregateOperator.java and dml.runtime.matrix)
      Returns:
        correct location

    - #### getCorrectionLocation

          public static Types.CorrectionLocationType getCorrectionLocation(Types.AggOp operation,
                                                                           Types.Direction direction)

    - #### setDimensionsBasedOnDirection

          public void setDimensionsBasedOnDirection(long dim1,
                                                    long dim2,
                                                    long blen)

    - #### setDimensionsBasedOnDirection

          public static void setDimensionsBasedOnDirection(Lop lop,
                                                           long dim1,
                                                           long dim2,
                                                           long blen,
                                                           Types.Direction dir)

    - #### toString

          public String toString()

      Description copied from class: `Lop`
      Method to have Lops print their state. This is for debugging purposes.
      Specified by:
        `toString` in class `Lop`

    - #### getInstructions

          public String getInstructions(String input1,
                                        String output)

      Instruction generation for for CP and Spark
      Overrides:
        `getInstructions` in class `Lop`
      Parameters:
        `input1` - input 1
        `output` - output
      Returns:
        instructions as string

    - #### getOpcode

          public static String getOpcode(Types.AggOp op,
                                         Types.Direction dir)

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