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）
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359
第 12 章
有用的方法
本章中介绍的方法既不是晦涩的数值计算，也不是高级的统计技术。但它们是有用的函
数和语法，你可能时不时地需要使用它们。
12.1 查看你的数据
12.1.1 问题
有许多数据
—
多到不能一次性显示出来。尽管如此，你需要查看一些数据。
12.1.2 解决方案
使用 head 函数查看前几个或前几行数据：
head(
x
)
使用 tail 函数查看后几个或后几行数据：
tail(
x
)
或者可以在 RStudio 的交互式查看器中查看整个内容：
View(
x
)
12.1.3 讨论
输出一个大的数据集毫无意义，因为它们不会全部展示在屏幕上。使用 head 函数来查
看一些数据（默认为 6 行 ）：
load(file = './data/lab_df.rdata')
360
｜
第
12
章
head(lab_df)
#> x lab y
#> 1 0.0761 NJ 1.621
#> 2 1.4149 KY 10.338
#> 3 2.5176 KY 14.284
#> 4 -0.3043 KY 0.599
#> 5 2.3916 KY 13.091
#> 6 2.0602 NJ 16.321
使用 tail 函数查看后几行数据和总行数：
tail(lab_df)
#> x lab y
#> 195 7.353 KY 38.880 ...
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