Knn slides (02) (Phương pháp Nearest Neighbor trong học máy) - Sebastian Raschka

UN
Uni24h
ダウンロード数: 0
46
0

資料の内容

1 ページ

Lecture 02 Nearest Neighbor Methods STAT 479: Machine Learning, Fall 2018 Sebastian Raschka http://stat.wisc.edu/~sraschka/teaching/stat479-fs2018/ 1

5 ページ

1-Nearest Neighbor Prediction Step closest_point := None closest_distance := for : current_distance := if current_distance < closest_distance: closest_distance := current_distance closest_point := return closest_point closest_point is the label of Sebastian Raschka STAT 479: Machine Learning FS 2018 !5

6 ページ

Commonly used: Euclidean Distance (L2) m 2 d(x[a],x[b]) = x[a] − x[b] ∑( j j ) j=1 Sebastian Raschka STAT 479: Machine Learning FS 2018 !6

10 ページ

a a Decision Boundary Between (a) and (c) d c Sebastian Raschka STAT 479: Machine Learning FS 2018 !10

13 ページ

Which Point is Closest? Euclid distan a c ? b Sebastian Raschka STAT 479: Machine Learning FS 2018 !13

14 ページ

a ? a ? b b Depends on the Distance Measure! Euclidean distance=1 Manhattan distance=1 a c ? ? b Sebastian Raschka STAT 479: Machine Learning FS 2018 !14

15 ページ

Continuous Distance Measures Euclidean Manhattan 1 Minkowski: m p p d(x[a],x[b]) = x[a] − x[b] [∑( ) ] j=1 Mahalanobis ... Sebastian Raschka STAT 479: Machine Learning FS 2018 !15

16 ページ

Discrete Distance Measures m Hamming: d(x[a],x[b]) = ∑ x[a] − x[b] j=1 Jaccard/Tanimoto Cosine similarity Dice ... Sebastian Raschka STAT 479: Machine Learning FS 2018 !16

17 ページ

Feature Scaling Euclidean Euclidean distance=1 distance=1 c c a ? a ? b b Euclidean Sebastian Raschka STAT 479: Machine Learning distance=1FS 2018Manhattan !17 distance=1

19 ページ

A y: Majority vote: Purality vote: B y: Majority vote: None Purality vote: Sebastian Raschka STAT 479: Machine Learning FS 2018 !19

20 ページ

kNN for Classification 𝒟 = {⟨x[1], f(x[1])⟩,…,⟨x[k], f(x[k])⟩} 𝒟k ⊆ 𝒟 k Sebastian Raschka STAT 479: Machine Learning FS 2018 !20

最初の20ページを表示しています。全文を見るには資料をダウンロードしてください。

コメント (0)

ログイン して議論に参加する

まだコメントはありません。最初のコメントを書きましょう!