MatrixSketch (Apache SystemDS 3.1.0 API)

All Known Implementing Classes:

CountDistinctFunctionSketch, CountDistinctSketch, KMVSketch
```
public interface MatrixSketch
```

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`CorrMatrixBlock`	`create(MatrixBlock blkIn)`	Create an initial sketch of a given block.
`MatrixBlock`	`getValue(MatrixBlock blkIn)`	Get scalar distinct count from an input matrix block.
`MatrixBlock`	`getValueFromSketch(CorrMatrixBlock blkIn)`	Obtain matrix distinct count value from estimation Used for estimating distinct in rows or columns.
`CorrMatrixBlock`	`intersection(CorrMatrixBlock arg0, CorrMatrixBlock arg1)`	Intersect two sketches
`CorrMatrixBlock`	`union(CorrMatrixBlock arg0, CorrMatrixBlock arg1)`	Union two sketches together to from a combined sketch.

- Method Detail
  - getValue
```
MatrixBlock getValue(MatrixBlock blkIn)
```
    Get scalar distinct count from an input matrix block.
    
    Parameters:
    
    blkIn - An input block to estimate the number of distinct values in
    
    Returns:
    
    The result matrix block containing the distinct count estimate
  - getValueFromSketch
```
MatrixBlock getValueFromSketch(CorrMatrixBlock blkIn)
```
    Obtain matrix distinct count value from estimation Used for estimating distinct in rows or columns.
    
    Parameters:
    
    blkIn - The sketch block to extract the count from
    
    Returns:
    
    The result matrix block
  - create
```
CorrMatrixBlock create(MatrixBlock blkIn)
```
    Create an initial sketch of a given block.
    
    Parameters:
    
    blkIn - A block to process
    
    Returns:
    
    A sketch
  - union
```
CorrMatrixBlock union(CorrMatrixBlock arg0,
                      CorrMatrixBlock arg1)
```
    Union two sketches together to from a combined sketch.
    
    Parameters:
    
    arg0 - Sketch one
    
    arg1 - Sketch two
    
    Returns:
    
    The sketch union is a sketch
  - intersection
```
CorrMatrixBlock intersection(CorrMatrixBlock arg0,
                             CorrMatrixBlock arg1)
```
    Intersect two sketches
    
    Parameters:
    
    arg0 - Sketch one
    
    arg1 - Sketch two
    
    Returns:
    
    The sketch intersection is a sketch