基本结构展示:
if (7<10) {
print("Seven is less than ten")
} else{
print("seven is more than ten")
}
实例演示:
Titanic=read.csv("https://goo.gl/4Gqsnz") #从网络读取数据
1. any() #any代表只要有任一值符合,即为TRUE
if (any(titanicC$Age>70)) {
print("there are passengers older than 70")
} else{
print("no one is older than 70")
}
2. all() #所有都满足才true
if (all(titanicC$Age>10)) {
print("all passengers older than 10")
} else{
print("there are passengers younger than 10")
}
3. na.omit() #放的位置决定是删除单一变量缺失值,还是删除任何变量缺失值
if (any(na.omit(titanic$Age==100))) {
print("there are passengers aged 100")
} else{
print("there are no passengers aged 100")
} #数据库中只要有missing的记录都删掉
if (any(titanic$Age==80, na.rm=TRUE)) {
print("there are passengers aged 80")
} else{
print("there are no passengers aged 80")
} #Age这个变量有missing的记录删掉,其他变量有missing可以保留
4. else if 写更重复的语句
x=100
y=10
if(x<y){
print("AA")
} else if(x==y){
print(BB)
} else{
print(CC)
}
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R语言:if-else条件判断及any、all、na.omit使用方法
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