April 2020
Intermediate to advanced
344 pages
8h 22m
Japanese
Content preview from Pythonではじめる教師なし学習 ―機械学習の可能性を広げるラベルなしデータの利用
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.
56
2
章 機械学習プロジェクトのはじめから終わりまで
図2-8 LightGB勾配ブースティングの適合率-再現率曲線（左）とauROC 曲線（右）
2.8
テストセットを用いた
4
つのモデルの検証
本章ではこれまでに以下のことを学んだ。
●
機械学習プロジェクトのための環境設定
●
データの取得、ロード、調査、クリーンアップ、可視化
●
データセットの訓練セットとテストセットへの分割と
k
分割交差検証セットの準備
●
適切なコスト関数の選択
●
ハイパーパラメータの設定と訓練と交差検証
●
結果の評価
ここでは、個々の機械学習に対して結果を良くし適合不足や過剰適合を避けるようにハイパーパラ
メータを調整すること（いわゆるハイパーパラメータチューニング）はしていないが、
GitHub
上のコー
ド（
https://github.com/aapatel09/handson-unsupervised-learning
）を使えば簡単にできるので各自試
してほしい。
パラメータの調整はしていないが、結果はかなり明らかだ。訓練と交差検証の結果から、
LightGBM
勾配ブースティングが最良で、
XGBoost
はそれよりはやや劣り、ランダムフォレストやロジスティック
回帰はかなり劣る。
テストセットを用いて、
4
つのモデルに対して最終的な評価を行ってみよう。
それぞれのモデルに対して、訓練で得たモデルを用いて、テストセットのトランザクションが不正か
どうかを予測する。そして各モデルが予測した不正確率と実際の不正ラベルを比較して、対数損失 ...
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.