November 2018
Intermediate to advanced
272 pages
6h 51m
Japanese
book
エレガントなSciPy ―Pythonによる科学技術計算
by Juan Nunez-Iglesias, Stéfan van der Walt, Harriet Dashnow, 山崎 邦子, 山崎 康宏
Content preview from エレガントなSciPy ―Pythonによる科学技術計算
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.
106
4 章 周波数と高速フーリエ変換
position
az
32
ビット浮動小数点数（
np.float32
）
el
32
ビット浮動小数点数（
np.float32
）
region_type
符号なし
8
ビット（
1
バイト）整数（
np.uint8
）
region_ID
符号なし
16
ビット（
2
バイト）整数（
np.uint8
）
gain
符号なし
8
ビット（
1
バイト）整数（
np.uint8
）
samples
2,048
個の符号なし
16
ビット（
2
バイト）整数（
np.uint8
）
NumPy
配列は均一（内部の全要素の型が同じ）であることは確かですが、上の例のように、
データが複合要素であっても構いません。
個々のフィールドデータには、辞書の構文規則を使ってアクセスできます。
azimuths = scan['position']['az'] # Get all azimuth measurements
すべての方位角の測定値を取得する。
本節では、測定値
v
sim
と
v
actual
は、複数ある対象物のそれぞれに反射された正弦波信号の総和
だということがわかりました。次の作業は、レーダの複合信号を構成する個々の成分を判定するこ
とです。それをやってくれるツールこそが
FFT
です。
4.7.1
周波数領域の信号特性
まず最初に、上の例の
3
つの信号（人工的な単一の標的、人工的な複数の標的、実測値）に対
して
FFT
を行い、正の周波数成分（
0
から
N/ 2
までの成分。図
4-22
を参照）を表示します。レー
ダ業界用語ではこれをレンジトレースと呼びます。
fig, ...
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.