January 2014
Beginner to intermediate
860 pages
20h 37m
Japanese
Content preview from Rクイックリファレンス 第2版
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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.
655
26
章
R
と
Hadoop
大規模なコンピューティング問題を高速化するための最善の手法は、多数の小さな
部分に分割し、各部分を別々に解決して元に戻す方法です。これは問題を並列に解決
できるので、並列コンピューティングと呼ばれます。例えば、たくさんの洗濯物があ
るとします。
10
台の洗濯機が一杯になるほどです。
1
回の洗濯には
45
分かかり、乾
燥に
45
分かかるとします。
1
台の洗濯機と
1
台の乾燥機しかなければ、洗濯物すべ
てを洗い終わるのに
495
分かかります。しかし、
10
台の洗濯機と
10
台の乾燥機があ
れば、
90
分で完了できます。
20
章と
21
章では、統計モデリングの最新手法を紹介しました。多くの問題は非常
に計算量が多く、完了に長い時間がかかります。幸い、その多くは簡単に並列化が可
能です。例えば、基盤となるデータに多数のツリーモデルをフィットさせてモデルを
構築するアルゴリズムをいくつか示しました（ブースティング、バギング、ランダム
フォレストなど）。これらのアルゴリズムは、複数のプロセッサが利用できれば並列
に実行できます。
R
には並列コンピューティングや分散コンピューティングに利用できるパッケージ
がたくさんあります。この章では、
Hadoop
ベースの解決策を重点的に取り上げます。
Hadoop
はすべての問題に最適な解決策ではありませんが、人気のあるオープンソー
スで、クラウドで優れた動作をします。
26.1
R
と
Hadoop
この数年間で、
Hadoop
はビッグデータを処理するためのデファクトスタンダード
になってきています。多くの人々にとって ...
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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.