将同一行中的日期减去一个因子R

Question

我有以下数据帧：

DF<-data.frame(stringsAsFactors = TRUE,
Sample = c(rep("s1",4),rep("s2",4)),
date = c("21/07/2020","24/07/2020","25/07/2020","27/07/2020",
"03/08/2020","06/08/2020","09/08/2020","10/08/2020"))

首先，我想通过因子"0"来获得连续日期之间的天数；样品"；。所以输出是这样的：

DF_2<-data.frame(stringsAsFactors = TRUE,
Sample = c(rep("s1",4),rep("s2",4)),
date = c("21/07/2020","24/07/2020","25/07/2020","27/07/2020",
"03/08/2020","06/08/2020","09/08/2020","10/08/2020"),
days = c(NA,3,1,2,NA,3,3,1))

其中变量"；天"；是我的结果变量。之后，我想添加所有这些"；天"；按因素。但这很容易，会这样做：

df_3<-aggregate(days~Sample,DF_2,sum)

如果有人帮我迈出正确的第一步，得到DF_2，我将不胜感激。

Answer 1

我们可以使用diff来获得Date类转换的"日期"列之间的差异

library(dplyr)
library(lubridate)
DF1 <- DF %>%
mutate(date = dmy(date)) %>% 
group_by(Sample) %>% 
mutate(days = c(NA, diff(date))) %>%
ungroup