# Package org.apache.sysds.runtime.compress.utils

- Class Summary
  Class | Description
  --- | ---
  ABitmap |
  Bitmap | Uncompressed representation of one or more columns in bitmap format.
  BitmapLossy | Uncompressed but Quantized representation of contained data.
  ColumnGroupIterator |
  CustomHashMap | This class provides a memory-efficient base for Custom HashMaps for restricted use cases.
  DblArray | Helper class used for bitmap extraction.
  DblArrayIntListHashMap | This class provides a memory-efficient replacement for `HashMap<DblArray,IntArrayList>` for restricted use cases.
  DoubleIntListHashMap | This class provides a memory-efficient replacement for `HashMap<Double,IntArrayList>` for restricted use cases.
  IntArrayList | This class provides a memory-efficient replacement for `ArrayList<Integer>` for restricted use cases.
  LinearAlgebraUtils | This library contains all vector primitives that are used in compressed linear algebra.

- Enum Summary
  Enum | Description
  --- | ---
  ABitmap.BitmapType |

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