August 2018
Intermediate to advanced
227 pages
4h 16m
Chinese
Content preview from 高效R语言编程
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110
｜
第
6
章
•
使用
tidyr
整理数据。
•
使用
dplyr
处理数据。
•
使用数据库。
•
使用
data.table
处理数据。
软件配置
本章需用到一些数据清理与处理的包。检查并确保它们已被安装，使用下列
命令加载它们：
library("tibble")
library("tidyr")
library("stringr")
library("readr")
library("dplyr")
library("data.table")
尽管
RSQLite
与
ggmap
不是本章的核心，但本章的几个例子中会用到它们。
高效数据木匠的
5
条高级技巧
1.
长远来看，项目的一开始花费时间准备数据可避免将来失败造成的大量时
间浪费。
2.
“整洁的数据”提供了组织数据的概念，
tidyr
包提供一些该方面的函数。
3.
tibble
包中的 data_frame 类使得数据集可高效输出并易于使用。
4. dplyr
提供了快速直观的数据处理函数；
data.table
在做某些数据处理应用
时，有着不可思议的速度。
5.
%>% 管道操作有助于理清复杂的数据处理流程。
高效的
tibble
数据框
tibble
包为
R
专门定义了新的数据框类 tbl_df。这些
tibble diffs
它们的创造
者所建议的发音，
https://github.com/hadley/tibble
）类似基础类 data.frame，
高效数据木匠
｜
111
但它们具有更人性化的打印、子集提取和因子操作。
一个
tibble
数据框是一个包含三个类的
S3
对象，分别是 tbl_df ...
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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.