October 2014
Intermediate to advanced
288 pages
6h 27m
Japanese
Content preview from 実践 機械学習システム
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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.
3.3
クラスタリング
61
図3-3
3.3.2
テストデータを用いて評価を行う
これまで見てきた簡単な例はここで終わりにします。クラスタリングの評価を行うため、評価が行え
るようなデータセットを用いて、私たちがこれまで考えてきたアプローチを評価したいと思います。そ
のために、「技術」をテーマとした文書で、すでにグループ分けされているモノを用います。すでにグ
ループ分けがされているため、アルゴリズムが期待通り分類できるかどうか評価することができます。
よく使われるデータセットの一つに、「20newsgroup」というデータセットがあります。これは、20個
のニュースグループから集められた18,826個の文書が含まれています。ニュースグループには、
comp.sys.mac.hardwareやsci.cryptといった技術系を扱うサイトや、talk.politics.guns、soc.religion.
christianといった政治や宗教
に関連したサイトなど、様々な分野が含まれます。ここでは、技術系を
扱うグループだけを対象とします。そして、技術系の各ニュースグループが各文書が属するクラスタ
であると見なすことにします。そうすることで、各文書の正解となるラベル（クラスタ）がわかってい
るため、都合良く評価を行うことができます。
データセットは、
http://people.csail.mit.edu/jrennie/20Newsgroups
からダウン
クラスタリング（２回目のループ）
単語１の重み
62
3
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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.