您可以按位置分组：

library(tidyverse)
library(zoo)

some_data <- rbind(tibble(day = 1:5,location = c(rep("A",5))),
                   tibble(day = 1:5,location = c(rep("B",5))))

some_data <- some_data %>% group_by(location) %>%
  mutate(roll_mean_left = rollmean(day, k = 3, fill = NA, align='left'),
         roll_mean_right = rollmean(day, k = 3, fill = NA, align='center'),
         roll_median_center = rollmedian(day, k = 3, fill = NA, align = 'right'))

some_data

滚动函数会为每个位置重新初始化。
注意滚动窗口如何根据align参数移动：

day location roll_mean_left roll_mean_right roll_median_center
   <int> <chr>             <dbl>           <dbl>              <dbl>
 1     1 A                     2              NA                 NA
 2     2 A                     3               2                 NA
 3     3 A                     4               3                  2
 4     4 A                    NA               4                  3
 5     5 A                    NA              NA                  4
 6     1 B                     2              NA                 NA
 7     2 B                     3               2                 NA
 8     3 B                     4               3                  2
 9     4 B                    NA               4                  3
10     5 B                    NA              NA                  4

小提示：

mutate(roll_mean_left = rollmean(day, k = 3, fill = NA, align='left'),
     roll_mean_right = rollmean(day, k = 3, fill = NA, align='center'),
     roll_median_center = rollmedian(day, k = 3, fill = NA, align = 'right'))

是有点误导，我想这是注定的

mutate(roll_mean_left = rollmean(day, k = 3, fill = NA, align='left'),
     roll_mean_right = rollmean(day, k = 3, fill = NA, align='right'),
     roll_median_center = rollmedian(day, k = 3, fill = NA, align = 'center'))

注意“align=”子句的更改以匹配变量名。