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commit 9aab798e75913d9374f54998b5589a2c06726857
parent 687944929926077b86170dea30e501224caaf435
Author: Andrew <andrewlaack1@gmail.com>
Date:   Mon, 11 Nov 2024 15:56:15 -0600

took some notes on dsa

Diffstat:
MAlgorithms.md | 4++--
MBinaryCode.md | 2+-
ACodeword.md | 10++++++++++
AEntropy.md | 16++++++++++++++++
4 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/Algorithms.md b/Algorithms.md @@ -75,9 +75,9 @@ Ch 5 (Hashing) Ch 6 (Information Theory and Data Compression) - InformationTheory - - Codeword + - [Codeword](Codeword.md) - [BinaryCode](BinaryCode.md) - - Entropy (define with probabilities (H(X) instead of IC(X))) + - [Entropy](Entropy.md) - [InformationContent](InformationContent.md) - RootedTree diff --git a/BinaryCode.md b/BinaryCode.md @@ -5,6 +5,6 @@ Ch 6 ## Notes -**Definition:** A binary code for S is a function from S -> {0,1} * . +**Definition:** A binary code for S is a function c from S -> {0,1} * . Basically, this is the function to encode elements of S to binary. diff --git a/Codeword.md b/Codeword.md @@ -0,0 +1,10 @@ +:cs: :data-structures: +# Codeword + +Ch 6 + +## Notes + +**Definition:** A codeword is an element c(x) where c is a binary code and x is a message. + +Remember, a binary code is defined as c : S -> {0,1}\*. diff --git a/Entropy.md b/Entropy.md @@ -0,0 +1,16 @@ +:data-structures: :cs: +# Entropy + +Ch 6 + +## Notes + +**Definition:** Entropy is the average number of bits communicated by one message if message hoarding is allowed. + +Entropy of a finite set of messages is denoted as H(X). + +Formula: + +$H(X) = -\sum_{x\in S} P(x)log_2(P(x))$ + +X is an ordered pair (S,P) where S is a finite set of messages and P is a function from S -> [0,1] S.T. P(x) = Probability of x for all x in S.