jm + frequency-tables   1

"A New Data Structure For Cumulative Frequency Tables"
paper by Peter M Fenwick, 1993. 'A new method (the ‘binary indexed tree’) is presented for maintaining the cumulative frequencies which are needed to support dynamic arithmetic data compression. It is based on a decomposition of the cumulative frequencies into portions which parallel the binary representation of the index of the table element (or symbol). The operations to traverse the data structure are based on the binary coding of the index. In comparison with previous methods, the binary indexed tree is faster, using more compact data and simpler code. The access time for all operations is either constant or proportional to the logarithm of the table size. In conjunction with the compact data structure, this makes the new method particularly suitable for large symbol alphabets.'

via Jakob Buchgraber, who's implementing it right now in Netty ;)
netty  frequency-tables  data-structures  algorithms  coding  binary-tree  indexing  compression  symbol-alphabets 
may 2014 by jm

Copy this bookmark:



description:


tags: