两个日期时间显示错误的输出之间的差异

Question

我想每3400秒至3600秒保持一个记录，这片代码会与下一行一起检查第一行，如果ID相同，则会检查时间是否分开3400或更多，如果是的。返回true，如果不是，则它将返回false。但是，正如您可以从下面的输出中看到的那样，它将从12:00:23到13:00:09返回False（因为两者之间的行是False）。有没有办法修改它，以便它会给我我所需的输出（如下）吗？

TIA

数据：

id<-c('8959', '8959', '8959', '8959', '8959', '8959', '8959','8959',
'8959', '8959', '8959', '8959', '8959','8959', '8959', '8959', '8959', 
'8959', '8959', '8959','8959','8959', '8959', '8959', 
'8959', '8959','8959','8959','8959','8959')

t<-c('2021-08-14 06:00:53', '2021-08-14 07:00:10','2021-08-14 08:00:20',
     '2021-08-14 09:00:30','2021-08-14 10:00:10','2021-08-14 11:00:11',
     '2021-08-14 12:00:23','2021-08-14 12:10:09','2021-08-14 12:20:08',
     '2021-08-14 12:30:13','2021-08-14 12:40:13','2021-08-14 12:50:21',
     '2021-08-14 13:00:09','2021-08-14 13:10:08','2021-08-14 13:20:53',
     '2021-08-14 13:30:08', '2021-08-14 13:40:09', '2021-08-14 13:50:08',
     '2021-08-14 14:00:20','2021-08-14 14:10:08','2021-08-14 14:20:09',
     '2021-08-14 14:30:20','2021-08-14 14:40:15','2021-08-14 15:00:08',
     '2021-08-14 16:00:12','2021-08-14 16:26:18','2021-08-14 16:30:09',
     '2021-08-14 17:00:13','2021-08-14 18:00:53','2021-08-14 19:00:36')

library(lubridate)

oc.df<-as.data.frame(cbind(id,t))
oc.df$t<-ymd_hms(oc.df$t)

代码块：

ind.data <- oc.df %>%
  group_by(id) %>%
  mutate(difftime = as.numeric(hms::as_hms(t) - hms::as_hms(lag(t, 1)))/3400) %>%
  mutate(independent = case_when(
    is.na(difftime) ~ TRUE,
    difftime >= 1 ~ TRUE,
    difftime < 1 ~ FALSE,
    TRUE ~ FALSE)
  )

当前输出：

t                   id      difftime.     independent
2021-08-14 06:00:53 8959    -18.141785714 FALSE
2021-08-14 07:00:10 8959    1.270357143   TRUE
2021-08-14 08:00:20 8959    1.289285714   TRUE
2021-08-14 09:00:30 8959    1.289285714   TRUE
2021-08-14 10:00:10 8959    1.278571429   TRUE
2021-08-14 11:00:11 8959    1.286071429   TRUE
2021-08-14 12:00:23 8959    1.290000000   TRUE
2021-08-14 12:10:09 8959    0.209285714   FALSE
2021-08-14 12:20:08 8959    0.213928571   FALSE
2021-08-14 12:30:13 8959    0.216071429   FALSE
2021-08-14 12:40:13 8959    0.214285714   FALSE
2021-08-14 12:50:21 8959    0.217142857   FALSE
2021-08-14 13:00:09 8959    0.210000000   FALSE
2021-08-14 13:10:08 8959    0.213928571   FALSE
2021-08-14 13:20:53 8959    0.230357143   FALSE
2021-08-14 13:30:08 8959    0.198214286   FALSE
2021-08-14 13:40:09 8959    0.214642857   FALSE
2021-08-14 13:50:08 8959    0.213928571   FALSE
2021-08-14 14:00:20 8959    0.218571429   FALSE
2021-08-14 14:10:08 8959    0.210000000   FALSE
2021-08-14 14:20:09 8959    0.214642857   FALSE
2021-08-14 14:30:20 8959    0.218214286   FALSE
2021-08-14 14:40:15 8959    0.212500000   FALSE
2021-08-14 15:00:08 8959    0.426071429   FALSE
2021-08-14 16:00:12 8959    1.287142857   TRUE
2021-08-14 16:26:18 8959    0.559285714   FALSE
2021-08-14 16:30:09 8959    0.082500000   FALSE
2021-08-14 17:00:13 8959    0.644285714   FALSE
2021-08-14 18:00:53 8959    1.300000000   TRUE
2021-08-14 19:00:36 8959    1.279642857   TRUE

所需的输出：

t                   id      difftime.     independent
2021-08-14 06:00:53 8959    -18.141785714 FALSE
2021-08-14 07:00:10 8959    1.270357143   TRUE
2021-08-14 08:00:20 8959    1.289285714   TRUE
2021-08-14 09:00:30 8959    1.289285714   TRUE
2021-08-14 10:00:10 8959    1.278571429   TRUE
2021-08-14 11:00:11 8959    1.286071429   TRUE
2021-08-14 12:00:23 8959    1.290000000   TRUE
2021-08-14 13:00:09 8959    0.210000000   TRUE
2021-08-14 14:00:20 8959    0.218571429   TRUE
2021-08-14 15:00:08 8959    0.426071429   TRUE
2021-08-14 16:00:12 8959    1.287142857   TRUE
2021-08-14 17:00:13 8959    0.644285714   TRUE
2021-08-14 18:00:53 8959    1.300000000   TRUE
2021-08-14 19:00:36 8959    1.279642857   TRUE