---
title: "Lesson 6"
format: html
---




```{r}

https://rs1.drwater.net

username: 
  - ruser01
  - ruser02
  - ruser03
  - ruser04
  - ruser05
  - ruser06

RWEP2025

```


# 安装包


```{r}
install.packages("tidyverse")

x <- c(1:10, NA)

hist(x)

mean(x, na.rm = TRUE)

median(x, na.rm = TRUE)

sd(x, na.rm = TRUE)


for(i in 1:10){
  print(i)
}


x + y + x * y

myfunc <- function(x, y = 3) {
  x + y + x * y
}


myfunc(1, 2)


myfunc(10)


c(FALSE, 2, 1:3, 3) 

c(FALSE, 2, 1:3, 3) > 1

all(c(FALSE, 2, 1:3, 3) > 1)


c(1L,2L,3L)

any(c(FALSE, 2, 1:3, 3) > 1)


x <- 10

sin(x) = ?

paste("sin(x) = ", sin(x), sep = " ")

paste0("sin(x) = ", sin(x))


substr("Monday", 1, 3)



```





