返回r中多个数据帧的日期与给定日期最接近的行

Question

我有9个不同长度的时间序列数据帧，每个数据帧用于不同的位置。我正试图找到一种方法来输入一个日期，并让R输出包含最接近我的输入日期的所有数据帧的行。

现在，我一直在做这个:

#bring in data
MNT <- read_excel("MNT_temporal.xlsx")
#change date format
MNT$date <- ymd_hms(MNT$date)
#specifying input date
date <- ymd_hms("2017-09-11 15:47:35")
#find which row is closest to input date
which.min(abs(date - MNT$date))
[1] 6 #R returns row with closest date
MNT[6,] #view data
# A tibble: 1 x 4
date                number.of.positives percent_inundated avg_depth_inundated
<dttm>                            <dbl>             <dbl>               <dbl>
1 2017-09-11 15:45:00                   0                 0                  NA

下面是我的一个位置(MNT)的数据示例:

# A tibble: 9 x 4
date                number.of.positives percent_inundated avg_depth_inundated
<dttm>                            <dbl>             <dbl>               <dbl>
1 2017-09-11 14:05:00                   0                 0                  NA
2 2017-09-11 14:25:00                   0                 0                  NA
3 2017-09-11 14:45:00                   0                 0                  NA
4 2017-09-11 15:05:00                   0                 0                  NA
5 2017-09-11 15:25:00                   0                 0                  NA
6 2017-09-11 15:45:00                   0                 0                  NA
7 2017-09-11 16:05:00                   0                 0                  NA
8 2017-09-11 16:25:00                   0                 0                  NA
9 2017-09-11 16:45:00                   0                 0                  NA

其余的位置命名如下:

#bring in data
MUT <- read_excel("MUT_temporal.xlsx")
MLT <- read_excel("MLT_temporal.xlsx")
MST <- read_excel("MST_temporal.xlsx")
MOL <- read_excel("MOL_temporal.xlsx")
PNT <- read_excel("PNT_temporal.xlsx")
PUT <- read_excel("PUT_temporal.xlsx")
PLT <- read_excel("PLT_temporal.xlsx")
PST <- read_excel("PST_temporal.xlsx")

是否有一种方法可以同时为所有位置做到这一点?

Answer 1

这样怎么样?

my_function<-function(filename){
#bring in data
file <- read_excel(filename)

#change date format
file$date <- ymd_hms(file$date)

#specifying input date
date <- ymd_hms("2017-09-11 15:47:35")

#find which row is closest to input date
rowindex<-which.min(abs(date - file$date))

return(file[rowindex,])

}
alllocations<-paste0(c("MNT","MUT","MLT","MST","MOL","PNT","PUT","PLT","PST"),"_temporal.xlsx")
savedates<-data.frame("date"=rep(0,length(alllocations)),"number.of.positives"=0, "percent_inundated"=0, "avg_depth_inundated"=0)
for(i in 1:length(alllocations)){

savedates[i,]<-my_function(alllocations[i])

}