> For the complete documentation index, see [llms.txt](https://euclid-jie.gitbook.io/euclid_jie_s_book/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://euclid-jie.gitbook.io/euclid_jie_s_book/r-yu-yan-cao-zuo.md).

# R语言

用于记录`R`语言的一些语法操作，主要为研究生期间的课程所学

## 基础操作

### 数据读写

* 读取`csv`文件

  ```R
  data <- read.csv("fileName.csv")  
  ```
* 读取`txt`数据

  ```
  data <- read.table("energy.txt",header = TRUE,sep = '\t')            # 读取数据
  ```

### 数据切片

使用`subset`对数据框进行切片

```R
onedayData <- subset(data,data$TimeStamp=='2020/02/27 00:00:00+00')
```

### 聚合查询

类似于`python`的`groupby`

```R
ConfirmedCovidCases <- aggregate(data$ConfirmedCovidCases, by=list(type=data$CountyName),max)
```

### 随机数

* 设置随机种子

  ```R
  set.seed(1234)
  ```
* 随机生产序列

  ```R
  x1 <- rnorm(50,4,2)
  e <- rnorm(50,0,0.1)
  y <- -2 + x1 + e
  ```

  ![随机生产的序列](https://euclid-picgo.oss-cn-shenzhen.aliyuncs.com/image/image-20221124145033909.png)

## 库地址

* [ggplot2](https://ggplot2.tidyverse.org)