Machine Learning, Decision Tree, Information Gain, Entropy.
node: Gain(S,Weather) = ? Sunny = 3 (1 Cinema + 2 Tennis) Windy = 4 (3 Cinema + 1 Shopping) Rainy = 3 (2 Cinema + 1 Home) Entropy(Ssunny)= — (1/3)*log2(1/3) — (2/3)*log2(2/3) = 0.918 Entropy(Swindy)= — (3/4)*log2(3/4) — (1/4)*log2(1/4) = 0.811 Entropy(Srainy)= — (2/3)*log2(2/3) — (1/3)*log2(1/3) =