August 2015
Intermediate to advanced
312 pages
7h 28m
Japanese
Content preview from 初めてのSpark
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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.
275
C.5 Spark のチューニング
No.
ー ーー ム
(MB)
4 77,865,758 7,694,202 1,097,982 0.999991 1,113
5 97,967,251 8,797,225 1,334,746 0.999992 1,400
6 116,938,309 9,734,990 1,563,344 0.999992 1,677
7 134,976,806 10,489,833 1,830,912 0.999993 1,943
レコメンド精度は、入手済みのユーザーの嗜好情報を学習データと評価データに分割して、オフ
ライン評価を行います。評価指標には
F
尺度（
f-measure
）とユーザーのカバレッジ（
Coverage
）
を用います。
F
尺度とは、適合率（
precision
：予測値の何割が正解したか）と再現率（
recall
：正
解を何割予測できていたか）に基づいて決まる指標です。またユーザーのカバレッジとは、評価
データに存在するユーザーの何割にレコメンドできていたかを表す指標です。それぞれの計算方法
を
C-3
にまとめます。
C-3
Recommend
レコメンドされたユーザー×アイテム
Order
実際に購買のあったユーザー×アイテム
Match
レコメンドされた中で、実際に購買のあったユーザー×アイテム
Order-User
実際に購買のあったユーザー
Match-User
レコメンドされた中で実際に購買のあったユーザー
C.5
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and much more.
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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.