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.
11.7
LightGBM
を用いた画像クラス分類器
259
図 11-21 数字「5」を生成した画像
−
8, 9
11.7
LightGBM
を用いた画像クラス分類器
さて、
2
章で紹介した勾配ブースティングアルゴリズムの実装であるLightGBMを使って画像クラス
分類器を作ってみよう。
11.7.1
教師あり学習だけの場合
最初に作るものは、
5,000
個のラベル付き
MNIST
画像だけを用いる。このデータセットは、元の
MNIST
の
50,000
画像から削減して作ったもので、ラベル付きのサンプルが少量しか得られない実世界
での場合をシミュレートするために作った設定だ。勾配ブースティングや
LightGBM
については
2
章で
詳しく述べているのでここでは立ち入らない。
アルゴリズムのパラメータを設定しよう。
predictionColumns = ['0','1','2','3','4','5','6','7','8','9']
params_lightGB = {
'task': 'train',
'application':'binary',
'num_class':10,
'boosting': 'gbdt',
'objective': 'multiclass',
'metric': 'multi_logloss',
'metric_freq':50,
'is_training_metric':False,
'max_depth':4,
'num_leaves': 31,
'learning_rate': 0.1, ...
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.