方法4： 采用 for + switch 语句
1: 自定义函数
# digital was translated into englishname
Month_name_for_switch<-function(month){
Month_name<-c()
for (i in 1:length(month)){
Month_name[i]<-switch(as.character(month[i]),
"1"="Jan","2"="Feb","3"="Mar",
"4"="Apr","5"="May", "6"="Jun",
"7"="Jul","8"="Aug", "9"="Sep",
"10"="Oct","11"="Nov","12"="Dec"
)
}
return(Month_name)
}
# season data
Season_name_for_switch<-function(month){
Season_name<-c()
for (i in 1:length(month)){
Season_name[i]<-switch(as.character(month[i]),
"1"="winter","2"="winter","3"="spring",
"4"="spring","5"="spring", "6"="summer",
"7"="summer","8"="summer", "9"="autumn",
"10"="autumn","11"="autumn","12"="winter"
)
}
return(Season_name)
}
result_for_switch<-function(month){
Month_name_for_switch<-Month_name_for_switch(month)# months' names
Season_name_for_switch<-Season_name_for_switch(month) #seasons' names
df<-data.frame(month,Month_name_for_switch,Season_name_for_switch)
return(df)
}
2: 调用函数进行运算
month<-month_digital(10)
Month_name_for_switch(month)
Season_name_for_switch(month)
microbenchmark::microbenchmark(Month_name_for_switch(month))
microbenchmark::microbenchmark(Season_name_for_switch(month))
microbenchmark::microbenchmark(result_for_switch(month))
Unit: microseconds
expr min lq mean median uq max
Month_name_for_switch(month) 17.17 17.718 93.07517 17.958 18.333 7425.695
neval
100
Unit: microseconds
expr min lq mean median uq max
Season_name_for_switch(month) 16.981 17.5185 87.48225 17.7105 17.952 6984.314
neval
100
Unit: microseconds
expr min lq mean median uq max
result_for_switch(month) 670.175 682.519 772.8128 692.1065 704.6855 4726.116
neval
100
(未完！待续……)
