July 2018
Intermediate to advanced
596 pages
13h 35m
Japanese
Content preview from Pythonによるデータ分析入門 第2版 ―NumPy、pandasを使ったデータ処理
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.
294
9
章 プロットと可視化
つは
bbox_inches
で、これを指定すると、図の本体のまわりの空白を取り除けます。先ほどの図の保存
を
PNG
で、まわりの空白を最小にして、
400 dpi
で行いたい場合は、コードは次のようになるでしょう。
plt.savefig('figpath.png', dpi=400, bbox_inches='tight')
savefig
を使うのは、ディスクに書き出したい場合だけではありません。
BytesIO
など、ファイル系
のオブジェクトであればどんなものにでも書き出せます。
from io import BytesIO
buffer = BytesIO()
plt.savefig(buffer)
plot_data = buffer.getvalue()
savefig
のオプションについては、いくつかを表9-2にまとめていますので、参照してください。
表9-2 Figure.savefigのオプション
引数 説明
fname
ファイルのパスを含む文字列か、
Python
のファイル系オブジェクト。ファイル形式
はファイルの拡張子から推測される（例えば
.pdf
なら
PDF
、
.png
なら
PNG
）。
dpi
1
インチ当たりのドット数（
dots per inch
）での、図の解像度。デフォルトは
100
だが、
設定によりデフォルト値を変えられる。
facecolor, edgecolor
図のサブプロット外側の背景色。デフォルトは
'w'
（白）。
format
使用するファイル形式の明示的な指定（
'png' ...
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.