org.apache.sysds.runtime.compress.bitmap

Class MultiColBitmap

java.lang.Object

org.apache.sysds.runtime.compress.bitmap.ABitmap

org.apache.sysds.runtime.compress.bitmap.MultiColBitmap

public final class MultiColBitmap
extends ABitmap

Uncompressed representation of one or more columns in bitmap format.

Method Summary

Modifier and Type	Method and Description
int	getNumColumns()
int	getNumNonZerosInOffset(int idx)
int	getNumValues() Obtain number of distinct value groups in the column.
double[][]	getValues() Get all values without unnecessary allocations and copies.
double[]	getValues(int ix) Obtain tuple of column values associated with index.
void	sortValuesByFrequency()

Methods inherited from class org.apache.sysds.runtime.compress.bitmap.ABitmap

containsZero, getNumOffsets, getNumOffsets, getNumZeros, getOffsetList, getOffsetsList, isEmpty, toString

Methods inherited from class java.lang.Object

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

Method Detail

getValues

public double[][] getValues()

Get all values without unnecessary allocations and copies.

Returns:

dictionary of value tuples

getValues

public double[] getValues(int ix)

Obtain tuple of column values associated with index.

Parameters:

ix - index of a particular distinct value

Returns:

the tuple of column values associated with the specified index

getNumNonZerosInOffset

public int getNumNonZerosInOffset(int idx)

Specified by:

getNumNonZerosInOffset in class ABitmap

getNumValues

public int getNumValues()

Description copied from class: ABitmap

Obtain number of distinct value groups in the column. this number is also the number of bitmaps, since there is one bitmap per value

Specified by:

getNumValues in class ABitmap

Returns:

number of distinct value groups in the column;

sortValuesByFrequency

public void sortValuesByFrequency()

Specified by:

sortValuesByFrequency in class ABitmap

getNumColumns

public int getNumColumns()

Specified by:

getNumColumns in class ABitmap