Class BitmapEncoder

  • public class BitmapEncoder
    extends Object
    Static functions for extracting bitmaps from a MatrixBlock.
    • Constructor Detail

      • BitmapEncoder

        public BitmapEncoder()
    • Method Detail

      • extractBitmap

        public static ABitmap extractBitmap​(IColIndex colIndices,
                                            MatrixBlock rawBlock,
                                            boolean transposed,
                                            int estimatedNumberOfUniques,
                                            boolean sortedEntries)
        Generate uncompressed bitmaps for a set of columns in an uncompressed matrix block. if the rawBlock is transposed and sparse it should be guaranteed that the rows specified are not empty, aka all zero.
        colIndices - Indexes (within the block) of the columns to extract
        rawBlock - An uncompressed matrix block; can be dense, sparse, empty, or null (not Compressed!)
        transposed - Boolean specifying if the rawBlock was transposed.
        estimatedNumberOfUniques - The number of estimated uniques inside this group. Used to allocated the HashMaps.
        sortedEntries - Boolean specifying if the entries should be sorted based on frequency of tuples
        Uncompressed bitmap representation of the columns specified