方法3： 采用 for + ifelse 语句
1: 自定义函数
# digital was translated into englishname
Month_name_for_ifelse<-function(month){
Month_name<-c()
for (i in 1:length(month)){
ifelse (month[i]==1, Month_name[i]<-"Jan",
ifelse (month[i]==2, Month_name[i]<-"Feb",
ifelse (month[i]==3, Month_name[i]<-"Mar",
ifelse (month[i]==4, Month_name[i]<-"Apr",
ifelse (month[i]==5, Month_name[i]<-"May",
ifelse (month[i]==6, Month_name[i]<-"Jun",
ifelse (month[i]==7, Month_name[i]<-"Jul",
ifelse (month[i]==8, Month_name[i]<-"Aug",
ifelse (month[i]==9, Month_name[i]<-"sep",
ifelse (month[i]==10, Month_name[i]<-"Oct",
ifelse (month[i]==11, Month_name[i]<-"Nov",
Month_name[i]<-"Dec")
)
)
)
)
)
)
)
)
)
)
}
return(Month_name)
}
# season data
Season_name_for_ifelse<-function(month){
Season_name<-c()
for (i in 1:length(month)){
ifelse((month[i]==1 | month[i]==2 | month[i]==12), Season_name[i]<-"Winter",
ifelse ((month[i]==3|month[i]==4|month[i]==5), Season_name[i]<-"Spring",
ifelse ((month[i]==6|month[i]==7|month[i]==8), Season_name[i]<-"Summer",
Season_name[i]<-"autumn")
)
)
}
return(Season_name)
}
result_for_ifelse<-function(month){
Month_name_for_ifelse<-Month_name_for_ifelse(month)# months' names
Season_name_for_ifelse<-Season_name_for_ifelse(month) #seasons' names
df<-data.frame(month,Month_name_for_ifelse,Season_name_for_ifelse)
return(df)
}
2: 调用函数进行运算
month<-month_digital(10)
microbenchmark::microbenchmark(Month_name_for_ifelse(month))
microbenchmark::microbenchmark(Season_name_for_ifelse(month))
microbenchmark::microbenchmark(result_for_ifelse(month))
Unit: microseconds
expr min lq mean median uq
Month_name_for_ifelse(month) 176.362 181.3845 516.0331 190.1935 196.6265
max neval
32033.72 100
Unit: microseconds
expr min lq mean median uq max
Season_name_for_ifelse(month) 83.435 85.2445 316.2032 89.358 92.34 22765.35
neval
100
Unit: microseconds
expr min lq mean median uq max
result_for_ifelse(month) 906.764 916.8955 1007.159 931.0235 953.935 4943.058
neval
100
(未完，待续……)
