Mis on Byte Pair Encoding (BPE) algoritmi idee? Kirjeldage koolitusetappe.

Byte Pair Encoding (BPE) algorithm is a method of text compression and tokenization that replaces frequently occurring pairs of characters (bytes) with new unique characters, thereby reducing the length of the text and creating a subword vocabulary.

Steps to train BPE:

1. Initialization: Represent the text as a sequence of individual characters (bytes).
2. Frequency counting: Count the frequency of all adjacent character pairs in the text.
3. Merging: Find the pair of characters with the highest frequency and replace all its occurrences with a new character (subword).
4. Updating: Update the text by replacing the selected pairs and repeat the frequency counting for the new pairs.
5. Repeat: Continue merging pairs until the desired number of new characters is reached or no more frequent pairs remain.

In the end, a subword vocabulary is obtained, which is used for efficient tokenization and text compression, useful in NLP for working with rare words and morphology.