3.1 条件语句
###1.if(){ } 如果。。。...(T,"A","B")
ifelse(F,"A","B")
ifelse(c(T,T,T),"A","B")
ifelse(c(F,F,F),"A","B")
ifelse(c(T,F,F),"A","...(samples,"normal");k2
ifelse(k2,"normal","tumor")
#### (3)多个条件
i = 0
if (i>0){
print('+')
} else if...anti_join(test1,test2,by="name") ###反连接,左边表里在右边表里没有的会被留下来。...一些搞文件的函数----
dir() # 列出工作目录下的文件
dir(pattern = ".R$") #列出工作目录下以.R结尾的文件
file.create("douhua.txt") #用代码创建文件