June 2020
Beginner to intermediate
522 pages
9h 6m
Chinese
Content preview from R 语言经典实例（原书第 2 版）
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.
R
软件导览
｜
65
然而，你可能希望在不退出 R 软件的情况下保存工作空间，因为你知道当你关闭笔记本
电脑将其带回家时可能会导致数据丢失。在这种情况下，可以使用 save.image 函数。
工作空间存放于当前工作目录下的一个后缀名为
.RData
的文件中。当 R 启动时，计算
机会查找该文件，找到后用它初始化工作空间。
可惜的是，工作空间不会保存当前打开的图形：例如，当你退出 R 时，屏幕上的图表会
消失。工作空间也不会保存窗口位置或你对 RStudio 的设置。这就是为什么我们建议使
用 RStudio 项目并编写 R 脚本，以便可以重现你创建的所有内容。
3.3.4 另请参阅
有关设置工作目录的信息，请参阅 3.1 节。
3.4 查看历史命令记录
3.4.1 问题
你希望查看近期使用过的一系列命令。
3.4.2 解决方案
根据你要完成的任务，可以使用几种不同的方法来访问之前的命令历史记录。如果你位于
RStudio 控制台（console）窗格中，则可以按向上箭头以交互方式滚动浏览过去的命令。
如果要查看过去命令的列表，可以使用 history 函数或访问 RStudio 中的“历史记录”
（History）窗格以查看最近的输入：
history()
在 RStudio 中，在控制台中键入
history()
会打开“历史记录”（History）窗格（见
图 3-5 ）。你还可以通过光标单击该窗格进行打开。
图 3-5：RStudio“历史记录” （History）窗格
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.