将日期序列创建为数据框R中的新列

Question

我一直在努力完成一个简单的任务（我想）。

我有一个数据集，其中包含两列，分别包含开始日期和结束日期。我想提取开始日期和结束日期之间的所有月份，并将它们一起列在数据框的新列中。下一步将是为该列中列出的每个月创建假人。

我的输入数据如下：

Lon      Lat      Year    Start_date     End_date    

70.25    40.25    2000    10/01/2009     04/30/2010  

70.75    40.25    2000    05/01/2010     08/30/2010   

71.00    40.25    2000    07/07/2010     11/30/2010   

这是我想要获得的：

Lon       Lat    Year     start_date  end_date      Sequence

70.25    40.25    2000    10/01/2009   04/30/2010   10,11,12,1,2,3,4

70.75    40.25    2000    05/01/2010   08/30/2010   5,6,7,8

71.00    40.25    2000    07/01/2010   11/30/2010   7,8,9,10,11

最后一列包含start_date和end_date之间的所有月份（以数字表示）的列表。

这是我的暂定代码。

sequence <- Map(seq.dates, start_date, end_date, 
                 by = "months", format = "%m/%d/%y") ```

The code works fine and gives me a list with all the months from start to end date, which is what I was aiming at. However, I am not able to cope with the list then, as I do not find any good way to extract the values of the list into a new column of the dataframe, while keeping the structure (the levels). I have tried almost any suggested in stackoverflaw on how to extract values from the list, and nothing works.
So, I want to start over and change perspective. 

Is there any other way to redesign the function above in a way to produce a new column attached to my data, or a vector? AND NOT A LIST? Any help would be immensely appreciated. Thanks!

Answer 1

涉及dplyr和lubridate的一种可能性是：

df %>%
 rowwise() %>%
 mutate(Sequence = list(month(mdy(Start_date)):month(mdy(End_date))))

    Lon   Lat  Year Start_date End_date   Sequence 
  <dbl> <dbl> <int> <chr>      <chr>      <list>   
1  70.2  40.2  2000 10/01/2009 04/30/2010 <int [7]>
2  70.8  40.2  2000 05/01/2010 08/30/2010 <int [4]>
3  71    40.2  2000 07/07/2010 11/30/2010 <int [5]>