This is my day 4 homework of BIC by 生信星球.
The content for today is the introduction of R and R studio.
1. Installation of R project and R studio
Watch the tutorial video on bilibli: https://www.bilibili.com/video/BV1J44y1R7ci/?share_source=copy_web&vd_source=ba670d5a7ca081b044384f15866b88ef
All done.
an interesting exaple of r application:
代码语言：R复制plot(rnorm(50))
#plot() is a default scatterplot function in r.
#rnorm() generates n random numbers from a normal distribution with the mean and sd you specify. 
another example:
代码语言：R复制boxplot(iris$Sepal.Length~iris$Species,col = c("lightblue","lightyellow","lightpink"))
2. Change the appearence
Tools -> Appearence->Global options
3. Basic opereation of R
3.1 Managing working directory
Read a previous paper for this point.
https://mp.weixin.qq.com/s/G-LXN9P2HVLv9v0cvyFJMA
代码语言：R复制setwd() #设置工作目录
getwd() #查看工作目录3.2 Show the list of files
代码语言：R复制> dir()
> list.files()3.3 Mathematic calculation
add, minus, multiple, divide, and log (skip).
3.4 create variable
syntax: <-
代码语言：R复制x <- 1 2my question is what is the difference between <- and =?
3.5 delete variable
example:
代码语言：R复制a <- 5 #赋值 a
b <- 18 #赋值b
c <- 26 #赋值c
u <- a b #赋值u
rm(b) #删除 b
rm(u,c) #删除 u，c
rm(list = ls()) #清空所有变量tips： tab key for filling in the rest of command or file name as far as it can automatically.
3.6 check the history of commands
代码语言：R复制history()3.7 clean the console
fast keys:
ctrl l
