ifelse是if表达式的简化,用法ifelse(条件,表达式一,表达式二)表示如果当条件为真,则执行表达式一,否则执行表达式二。 > a <- 10 > ifelse(a>10, print("a大于10"), print("a小于等于10")) ##[1] "a小于等于10" > ifelse(b<=2, "x小于等于2", "x大于2") ##[1] "x小于等于2" "x小于等于2"
R if...elseIn computer programming, the if statement allows us to create a decision making program. A decision making program runs one block of code under a condition and another block of code under different conditions. For example, If age is greater than 18, allow the person to vote. ...
In this tutorial, we will learn what control statements in R programming are, and its types. Here, we will discuss If, If- Else and for loop in R programming.
大家还应该掌握的使用逻辑判断进行变量重新编码的方法，这个时候需要用到replace()，ifelse()andif_else()和case_when()，给大家写一个case_when的例子，这个函数就是在我们需要根据某个变量的值生成新变量的时候使用，比如我们根据age_unit的不同取值，生成新变量age_years，我们就可以用case_when()：raw %>% ...
# Control Structures: if-Else #===# ## Control Structures: if ## if if (x>3){ y<-10 }else{ y<- 0 } x <- 2 x y ## So is this one. y <- if(x>3){ 10 }else{ 0 } x <- 3 y y <- 12 x <- 2 y #===#...
If the condition returns a TRUE Boolean value, R routed inside the if block and process for the expression or programming logic written in that block. If it founds the FALSE Boolean value, it will not go inside the If block, rather it will check for next available else if block. ...
detach()detach("package:babynames",unload=TRUE) 四. R 程序控制 判断语句 循环语句 (一) 判断语句: if 语句 if...else 语句 switch 语句 其中, 1. if 语句: 由一个布尔表达式后跟一个或多个语句组成。 if(boolean_expression){//布尔表达式为真将执行的语句} 举例: x<-...
fib1<-function(n){if(n==0)return(0)elseif(n==1)return(1)elseif(n>=2){fib1(n-1)+fib1(n-2)}}>for(iin1:5)print(fib1(i))[1]1[1]1[1]2[1]3[1]5 但这样定义有个问题,当我们的原先的函数改名了,使用新被定义的函数执行代码,就会发生报错了: ...
}else{if(nrow(data_order[[i]])==2){ rank=c("a","d") }else{ rank=c("a",2:(nrow(data_order[[i]])-1),"d")}} 综上,这是我在做assignment3里被踩过的若干个坑…… 感谢我终于出来了 谢谢JHU贡献的这么有操作意义的R Programming的课程,接下来打算继续跟着学习cleanning data,听说assignme...
When we’re programming in R (or any other language, for that matter), we often want to controlwhenandhowparticular parts of our code are executed. We can do that usingcontrol structureslike if-else statements, for loops, and while loops. ...