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.
5.8
分類器をスリムにする
109
>>>
thresh80 = threshold[idx80][0]
>>>
probs_for_good = clf.predict_proba(answer_features)[:,1]
>>>
answer_class = probs_for_good>thresh80
また、
classification_report
というモジュールを用いて、適合率と再現率の値を確認するこ
とができます。
>>>
from sklearn.metrics import classification_report
>>>
print(classification_report(y_test, clf.predict_proba [:,1]>0.63,
target_names=['not accepted', 'accepted']))
precision recall f1-score
not accepted 0.63 0.93 0.75 108
accepted 0.80 0.36 0.50 92
avg / total 0.71 0.67 0.63 200
ここでは適切な閾値を求めてきましたが、その閾値を用いることで必ず期待している適合率
と再現率を満たすとは限りません。
5.8
分類器を“スリム”にする
各特徴量が分類を行うためにどれだけ貢献しているか、ということについて見識を得ることは常に
大切なことです。ロジスティック回帰の場合、学習した結果である回帰係数（
cl
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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.