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.
70
4
章 トピックモデル
の手法が、このLDAを基に提案されています。LDAを理解するためには、その背景として複雑な数
学の知識が必要ですが、ここでは詳細には立ち入らないことにします。
興味のある方は、次のWikipediaページを参照してください。LDAアルゴリズムの背景にある数式
について記載されています。
http://en.wikipedia.org/wiki/Latent_Dirichlet_allocation
詳細については省きましたが、このモデルのおおまかなイメージとしては、“文章製造機”のようなも
のがあり、それがこのモデルの背後にあると考えることができます。この文章製造機の中には、固定さ
れたトピックが存在します。少しわかりにくいと思うので、具体例を挙げて考えてみましょう。
たとえば、次の3つのトピックだけがある場合を考えてみましょう。
●
機械学習
●
Python
●
料理
各トピックは関連する単語のリストを持ちま
す。本書は、「機械学習」と「Python」の二つのトピッ
クから構成されると言えるでしょう。もしかしたら、50％ずつそれぞれのトピックについて書かれてい
るかもしれません。もしそうだとすると、私たちが本書を執筆したときに、「機械学習」のトピックが持
つ単語リストから、本書で使われる単語の半分が選び出されたことになります。そして、残り半分の
単語が、「Python」のトピックが持つ単語リストから選び出されます。ちなみに、このモデルでは単語
の順序については考えません。
もちろん、私た ...
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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.