org.apache.sysds.runtime.compress.colgroup

Class ColGroupEmpty

java.lang.Object

org.apache.sysds.runtime.compress.colgroup.AColGroup

org.apache.sysds.runtime.compress.colgroup.ColGroupCompressed

org.apache.sysds.runtime.compress.colgroup.ColGroupEmpty

All Implemented Interfaces:

Serializable

public class ColGroupEmpty
extends ColGroupCompressed

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.sysds.runtime.compress.colgroup.AColGroup

AColGroup.CompressionType

Constructor Summary

Constructors

Constructor and Description
ColGroupEmpty(int[] colIndices) Constructs an Constant Colum Group, that contains only one tuple, with the given value.

Method Summary

Modifier and Type	Method and Description
AColGroup	binaryRowOp(BinaryOperator op, double[] v, boolean sparseSafe, boolean left) Perform a binary row operation.
void	computeColSums(double[] c, int nRows) Compute the column sum
boolean	containsValue(double pattern) Detect if the column group contains a specific value.
AColGroup	copy() Get a copy of this column group.
void	countNonZerosPerRow(int[] rnnz, int rl, int ru) Count the number of non-zeros per row
void	decompressToBlock(MatrixBlock target, int rl, int ru, int offT) Decompress the contents of the column group without counting non zeros
static ColGroupEmpty	generate(int nCol)
double	get(int r, int c) Get the value at a global row/column position.
org.apache.sysds.runtime.compress.colgroup.AColGroup.ColGroupType	getColGroupType() Internally get the specific type of ColGroup, this could be extracted from the object but that does not allow for nice switches in the code.
AColGroup.CompressionType	getCompType() Obtain the compression type.
double	getMax() Short hand method for getting maximum value contained in this column group.
double	getMin() Short hand method for getting minimum value contained in this column group.
long	getNumberNonZeros(int nRows) Get the number of nonZeros contained in this column group.
int	getNumValues() Obtain number of distinct tuples in contained sets of values associated with this column group.
double[]	getValues() Get all the values in the colGroup.
MatrixBlock	getValuesAsBlock() Returns the ColGroup as a MatrixBlock.
boolean	isDense() Is dense, signals that the entire column group is allocated an processed.
boolean	isLossy() Is Lossy
void	leftMultByAColGroup(AColGroup lhs, MatrixBlock c) Left side matrix multiplication with a column group that is transposed.
void	leftMultByMatrix(MatrixBlock a, MatrixBlock c, int rl, int ru) Left multiply with this column group.
AColGroup	replace(double pattern, double replace) Make a copy of the column group values, and replace all values that match pattern with replacement value.
AColGroup	rightMultByMatrix(MatrixBlock right) Right matrix multiplication with this column group.
AColGroup	scalarOperation(ScalarOperator op) Perform the specified scalar operation directly on the compressed column group, without decompressing individual cells if possible.
void	tsmmAColGroup(AColGroup other, MatrixBlock result) Matrix multiply with this other column group, but: 1.

Methods inherited from class org.apache.sysds.runtime.compress.colgroup.ColGroupCompressed

tsmm, unaryAggregateOperations

Methods inherited from class org.apache.sysds.runtime.compress.colgroup.AColGroup

colSum, decompressToBlock, estimateInMemorySize, getColIndices, getExactSizeOnDisk, getNumCols, leftMultByMatrix, readFields, shiftColIndices, sliceColumn, sliceColumns, toString, write

Methods inherited from class java.lang.Object

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

Constructor Detail

ColGroupEmpty

public ColGroupEmpty(int[] colIndices)

Constructs an Constant Colum Group, that contains only one tuple, with the given value.

Parameters:

colIndices - The Colum indexes for the column group.

Method Detail

generate

public static ColGroupEmpty generate(int nCol)

getCompType

public AColGroup.CompressionType getCompType()

Description copied from class: AColGroup

Obtain the compression type.

Specified by:

getCompType in class AColGroup

Returns:

How the elements of the column group are compressed.

getColGroupType

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

Description copied from class: AColGroup

Internally get the specific type of ColGroup, this could be extracted from the object but that does not allow for nice switches in the code.

Returns:

ColGroupType of the object.

decompressToBlock

public void decompressToBlock(MatrixBlock target,
                              int rl,
                              int ru,
                              int offT)

Description copied from class: AColGroup

Decompress the contents of the column group without counting non zeros

Specified by:

decompressToBlock in class AColGroup

Parameters:

target - a matrix block where the columns covered by this column group have not yet been filled in.

rl - row lower

ru - row upper

offT - Offset into target to assign from, this allows us to decompress into smaller matrices.

get

public double get(int r,
                  int c)

Description copied from class: AColGroup

Get the value at a global row/column position. In general this performs poorly compared to a normal lookup in a dense or sparse matrix.

Specified by:

get in class AColGroup

Parameters:

r - row

c - column

Returns:

value at the row/column position

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

binaryRowOp

public AColGroup binaryRowOp(BinaryOperator op,
                             double[] v,
                             boolean sparseSafe,
                             boolean left)

Description copied from class: AColGroup

Perform a binary row operation.

Specified by:

binaryRowOp in class AColGroup

Parameters:

op - The operation to execute

v - The vector of values to apply, should be same length as dictionary length.

sparseSafe - True if the operation return 0 on all instances of values in v -- op(v[?], 0)

left - Specifies if the operation is executed on the left or right side of the values contained

Returns:

A updated column group with the new values.

countNonZerosPerRow

public void countNonZerosPerRow(int[] rnnz,
                                int rl,
                                int ru)

Description copied from class: AColGroup

Count the number of non-zeros per row

Specified by:

countNonZerosPerRow in class AColGroup

Parameters:

rnnz - non-zeros per row

rl - row lower bound, inclusive

ru - row upper bound, exclusive

getNumValues

public int getNumValues()

Description copied from class: AColGroup

Obtain number of distinct tuples in contained sets of values associated with this column group. If the column group is uncompressed the number or rows is returned.

Specified by:

getNumValues in class AColGroup

Returns:

the number of distinct sets of values associated with the bitmaps in this column group

getValues

public double[] getValues()

Description copied from class: AColGroup

Get all the values in the colGroup. Note that this is only the stored values not the way they are stored. Making the output a list of values used in that colGroup not the actual full column.

Specified by:

getValues in class ColGroupCompressed

Returns:

a double list of values.

isLossy

public boolean isLossy()

Description copied from class: AColGroup

Is Lossy

Specified by:

isLossy in class ColGroupCompressed

Returns:

returns if the ColGroup is compressed in a lossy manner.

getValuesAsBlock

public MatrixBlock getValuesAsBlock()

Description copied from class: AColGroup

Returns the ColGroup as a MatrixBlock. Used as a fall back solution in case a operation is not supported. Use in connection to getIfCountsType to get if the values are repeated.

Specified by:

getValuesAsBlock in class AColGroup

Returns:

Matrix Block of the contained Values. Possibly contained in groups.

leftMultByMatrix

public void leftMultByMatrix(MatrixBlock a,
                             MatrixBlock c,
                             int rl,
                             int ru)

Description copied from class: AColGroup

Left multiply with this column group.

Specified by:

leftMultByMatrix in class AColGroup

Parameters:

a - The matrix to multiply with on the left

c - The result to output the values into, always dense for the purpose of the column groups parallelizing

rl - The row to begin the multiplication from on the lhs matrix

ru - The row to end the multiplication at on the lhs matrix

leftMultByAColGroup

public void leftMultByAColGroup(AColGroup lhs,
                                MatrixBlock c)

Description copied from class: AColGroup

Left side matrix multiplication with a column group that is transposed.

Specified by:

leftMultByAColGroup in class AColGroup

Parameters:

lhs - The left hand side Column group to multiply with, the left hand side should be considered transposed.

c - The result matrix to insert the result of the multiplication into

tsmmAColGroup

public void tsmmAColGroup(AColGroup other,
                          MatrixBlock result)

Description copied from class: AColGroup

Matrix multiply with this other column group, but: 1. Only output upper triangle values. 2. Multiply both ways with "this" being on the left and on the right. The second step is achievable by treating the initial multiplied matrix, and adding its values to the correct locations in the output.

Specified by:

tsmmAColGroup in class AColGroup

Parameters:

other - The other Column group to multiply with

result - The result matrix to put the results into

isDense

public boolean isDense()

Description copied from class: AColGroup

Is dense, signals that the entire column group is allocated an processed. This is useful in Row wise min and max for instance, to avoid having to scan through each row to look for empty rows. an example where it is true is DDC, Const and Uncompressed. examples where false is OLE and RLE.

Specified by:

isDense in class AColGroup

Returns:

returns if the colGroup is allocated in a dense fashion.

copy

public AColGroup copy()

Description copied from class: AColGroup

Get a copy of this column group. Depending on which column group is copied it is a deep or shallow copy. If the primitives for the underlying column groups is Immutable then only shallow copies is performed.

Specified by:

copy in class AColGroup

Returns:

Get a copy of this column group.

containsValue

public boolean containsValue(double pattern)

Description copied from class: AColGroup

Detect if the column group contains a specific value.

Specified by:

containsValue in class AColGroup

Parameters:

pattern - The value to look for.

Returns:

boolean saying true if the value is contained.

getNumberNonZeros

public long getNumberNonZeros(int nRows)

Description copied from class: AColGroup

Get the number of nonZeros contained in this column group.

Specified by:

getNumberNonZeros in class AColGroup

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.

rightMultByMatrix

public AColGroup rightMultByMatrix(MatrixBlock right)

Description copied from class: AColGroup

Right matrix multiplication with this column group.

Specified by:

rightMultByMatrix in class AColGroup

Parameters:

right - The matrixBlock on the right of this matrix multiplication

Returns:

The new Column Group that is the result of the matrix multiplication.

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.

Specified by:

replace in class AColGroup

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.

getMin

public final double getMin()

Description copied from class: AColGroup

Short hand method for getting minimum value contained in this column group.

Overrides:

getMin in class ColGroupCompressed

Returns:

The minimum value contained in this ColumnGroup

getMax

public final double getMax()

Description copied from class: AColGroup

Short hand method for getting maximum value contained in this column group.

Overrides:

getMax in class ColGroupCompressed

Returns:

The maximum value contained in this ColumnGroup

computeColSums

public void computeColSums(double[] c,
                           int nRows)

Description copied from class: AColGroup

Compute the column sum

Overrides:

computeColSums in class ColGroupCompressed

Parameters:

c - The array to add the column sum to.

nRows - The number of rows in the column group.