R:按日期依次展开和填充数据框 [英] R: expand and fill data frame by date in series

问题描述

我有原始数据框:

igroup=c("A", "B", "C")
demo_df=data.frame(date=c("2018-11-28", "2018-12-17", "2019-01-23"), group)

原始数据框:

      date   group
1 2018-11-28     A
2 2018-12-17     B
3 2019-01-23     C

我想要一个将日期扩展到下一列但仍保留组信息的数据框.例如，2018-11-28 至 2018-12-16 为 A 组，2018-12-17 至 2019-01-22 为 B 组，2019-01-23 为 C 组.

I want to have a data frame that expand the date to next column but still keep the group information. For example, date from 2018-11-28 to 2018-12-16 is with group A, date from 2018-12-17 to 2019-01-22 is with group B and 2019-01-23 is with group C.

这是我想要的输出 (result_df):

This is the output (result_df) I want:

time=c(seq(as.Date("2018-11-28"), as.Date("2018-12-17")-1, by=1), 
seq(as.Date("2018-12-17"), as.Date("2019-01-23")-1, by=1),as.Date("2019-01-23") )
group1=c(rep("A",as.numeric(as.Date("2018-12-17")-as.Date("2018-11-28"))), 
rep("B",as.numeric(as.Date("2019-01-23")-as.Date("2018-12-17"))), "C" )
result_df=data.frame(time,group1 )
result_df

我想知道是否有更有效的方法(使用 dplyr)来处理这个问题.

I am wondering if there is any more efficient way (using dplyr) to handle this issue.

提前致谢.

推荐答案

首先，确保将 date 存储为日期对象:

First, make sure date is stored as a date object:

demo_df$date <- as.Date(demo_df$date, format = "%Y-%m-%d")

然后使用tidyverse，我们先完成序列，然后填充组:

Then using tidyverse, we first complete the sequence, then fill the group down:

library(tidyverse)

demo_df %>% complete(date = seq.Date(min(date), max(date), by = "day")) %>% 
 fill(igroup)

这篇关于R:按日期依次展开和填充数据框的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！