Package org.apache.sysds.runtime.compress.colgroup

Class ColGroupSDC

  • All Implemented Interfaces:
    Serializable, Cloneable
    public class ColGroupSDC
extends AMorphingMMColGroup
    Column group that sparsely encodes the dictionary values. The idea is that all values is encoded with indexes except the most common one. the most common one can be inferred by not being included in the indexes. This column group is handy in cases where sparse unsafe operations is executed on very sparse columns. Then the zeros would be materialized in the group without any overhead.
    See Also:
    Serialized Form

    • Method Detail

      • getColGroupType

        public org.apache.sysds.runtime.compress.colgroup.AColGroup.ColGroupType getColGroupType()

      • getIdx

        public double getIdx​(int r,
                     int colIdx)
        Description copied from class: AColGroup
        Get the value at a colGroup specific row/column index position.
        Specified by:
        getIdx in class AColGroup
        Parameters:
        r - row
        colIdx - column index in the _colIndexes.
        Returns:
        value at the row/column index position

      • computeColSums

        public void computeColSums​(double[] c,
                           int nRows)
        Description copied from class: AColGroup
        Compute the column sum
        Overrides:
        computeColSums in class AColGroupValue
        Parameters:
        c - The array to add the column sum to.
        nRows - The number of rows in the column group.

      • getNumberNonZeros

        public long getNumberNonZeros​(int nRows)
        Description copied from class: AColGroup
        Get the number of nonZeros contained in this column group.
        Overrides:
        getNumberNonZeros in class AColGroupValue
        Parameters:
        nRows - The number of rows in the column group, this is used for groups that does not contain information about how many rows they have.
        Returns:
        The nnz.

      • estimateInMemorySize

        public long estimateInMemorySize()
        Description copied from class: AColGroup
        Get the upper bound estimate of in memory allocation for the column group.
        Overrides:
        estimateInMemorySize in class AColGroupValue
        Returns:
        an upper bound on the number of bytes used to store this ColGroup in memory.

      • scalarOperation

        public AColGroup scalarOperation​(ScalarOperator op)
        Description copied from class: AColGroup
        Perform the specified scalar operation directly on the compressed column group, without decompressing individual cells if possible.
        Specified by:
        scalarOperation in class AColGroup
        Parameters:
        op - operation to perform
        Returns:
        version of this column group with the operation applied

      • binaryRowOpLeft

        public AColGroup binaryRowOpLeft​(BinaryOperator op,
                                 double[] v,
                                 boolean isRowSafe)
        Description copied from class: AColGroup
        Perform a binary row operation.
        Specified by:
        binaryRowOpLeft in class AColGroup
        Parameters:
        op - The operation to execute
        v - The vector of values to apply, should be same length as dictionary length.
        isRowSafe - True if the binary op is applied to an entire zero row and all results are zero
        Returns:
        A updated column group with the new values.

      • binaryRowOpRight

        public AColGroup binaryRowOpRight​(BinaryOperator op,
                                  double[] v,
                                  boolean isRowSafe)
        Description copied from class: AColGroup
        Perform a binary row operation.
        Specified by:
        binaryRowOpRight in class AColGroup
        Parameters:
        op - The operation to execute
        v - The vector of values to apply, should be same length as dictionary length.
        isRowSafe - True if the binary op is applied to an entire zero row and all results are zero
        Returns:
        A updated column group with the new values.

      • getExactSizeOnDisk

        public long getExactSizeOnDisk()
        Description copied from class: AColGroup
        Returns the exact serialized size of column group. This can be used for example for buffer preallocation.
        Overrides:
        getExactSizeOnDisk in class AColGroupValue
        Returns:
        exact serialized size for column group

      • replace

        public AColGroup replace​(double pattern,
                         double replace)
        Description copied from class: AColGroup
        Make a copy of the column group values, and replace all values that match pattern with replacement value.
        Overrides:
        replace in class AColGroupValue
        Parameters:
        pattern - The value to look for
        replace - The value to replace the other value with
        Returns:
        A new Column Group, reusing the index structure but with new values.

      • subtractDefaultTuple

        public AColGroup subtractDefaultTuple()

      • centralMoment

        public CM_COV_Object centralMoment​(CMOperator op,
                                   int nRows)
        Description copied from class: AColGroup
        Central Moment instruction executed on a column group.
        Overrides:
        centralMoment in class AColGroupValue
        Parameters:
        op - The Operator to use.
        nRows - The number of rows contained in the ColumnGroup.
        Returns:
        A Central Moment object.

      • rexpandCols

        public AColGroup rexpandCols​(int max,
                             boolean ignore,
                             boolean cast,
                             int nRows)
        Description copied from class: AColGroup
        Expand the column group to multiple columns. (one hot encode the column group)
        Overrides:
        rexpandCols in class AColGroupValue
        Parameters:
        max - The number of columns to expand to and cutoff values at.
        ignore - If zero and negative values should be ignored.
        cast - If the double values contained should be cast to whole numbers.
        nRows - The number of rows in the column group.
        Returns:
        A new column group containing max number of columns.

      • getCost

        public double getCost​(ComputationCostEstimator e,
                      int nRows)
        Description copied from class: AColGroup
        Get the computation cost associated with this column group.
        Specified by:
        getCost in class AColGroup
        Parameters:
        e - The computation cost estimator
        nRows - the number of rows in the column group
        Returns:
        The cost of this column group

      • containsValue

        public boolean containsValue​(double pattern)
        Description copied from class: AColGroup
        Detect if the column group contains a specific value.
        Overrides:
        containsValue in class AColGroupValue
        Parameters:
        pattern - The value to look for.
        Returns:
        boolean saying true if the value is contained.