April 2019
Beginner to intermediate
480 pages
12h 34m
Korean
Content preview from 파이썬 라이브러리를 활용한 머신러닝(번역개정판): 사이킷런 핵심 개발자가 쓴 머신러닝과 데이터 과학 실무서
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
3
장
비지도 학습과 데이터 전처리
249
그림
3-38
기본값
eps
=0.5를 사용해
DBSCAN
으로 찾은 클러스터 할당
이 알고리즘은 예상한 클러스터 개수(
2
개)를 만들어내므로 매개변수 설정이 잘 맞는 것 같습
니다.
eps
를 (기본값인
0
.
5
에서)
0
.
2
로 내리면 너무 많은
8
개의 클러스터를 만들어냅니다.
eps
를
0
.
7
로 올리면 클러스터를 하나만 만듭니다.
DBSCAN
을 사용할 때 클러스터 할당 값을 주의해서 다뤄야 합니다. 클러스터 레이블을 다른
배열의 인덱스로 사용할 경우 잡음 포인트를 의미하는 -
1
값이 예상치 못한 결과를 만들 수 있
기 때문입니다.
3.5.4
군집 알고리즘의 비교와 평가
군집 알고리즘을 적용하는 데 어려운 점 하나는 알고리즘이 잘 작동하는지 평가하거나 여러 알
고리즘의 출력을 비교하기가 매우 어렵다는 것입니다. 군집 알고리즘의 평가에 대해 이야기한
후 실제 데이터셋을 이용해
k
-평균, 병합 군집,
DBSCAN
알고리즘을 비교해보겠습니다.
타깃값으로 군집 평가하기
군집 알고리즘의 결과를 실제 정답 클러스터와 비교하여 평가할 수 있는 지표들이 있습니
다.
1
(최적일 때 )과
0
(무작위로 분류될 때) 사이의 값을 제공하는
ARI
adjusted
rand
index
40
와
NMI
normalized
mutual
information
41
가 가장 ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.