How to select/subset multiple time series data frames in a list with same dates-CodePudding

I have a list of data frames in the following fashion:

> Year<- c(1984, 1999, 2002, 2005, 2010)
> Val <- c(2,1,4,5,4)
> df1 <- cbind.data.frame(Year, Val)
> df1
  Year Val
1 1984   2
2 1999   1
3 2002   4
4 2005   5
5 2010   4

> Year<- c(1934, 1989, 2012, 2015, 2000)
> Val <- c(1,5,3,2,1)
> df2 <- cbind.data.frame(Year, Val)
> df2
  Year Val
1 1934   1
2 1989   5
3 2012   3
4 2015   2
5 2000   1

> Year <- c(1984, 1999, 2002, 2005, 2010)
> Val <- c(5,7,8,3,4.5)
> df3 <- cbind.data.frame(Year, Val)
> df3
  Year Val
1 1984 5.0
2 1999 7.0
3 2002 8.0
4 2005 3.0
5 2010 4.5

> c <- list(df1, df2, df3)
> c
[[1]]
  Year Val
1 1984   2
2 1999   1
3 2002   4
4 2005   5
5 2010   4

[[2]]
  Year Val
1 1934   1
2 1989   5
3 2012   3
4 2015   2
5 2000   1

[[3]]
  Year Val
1 1984 5.0
2 1999 7.0
3 2002 8.0
4 2005 3.0
5 2010 4.5

For my assignment I would like to select data frames from the list c, with the same Year values. So, that in another list, say d I have all the data frames from list c which have the same years. How to approach this problem? Thank you.

CodePudding user response：

We may use intersect i.e, extract the 'Year' column from the list, get the intersecting 'Year' values, and then do a subset to get the rows having only that 'Year' values in each of the list elements by looping over the list with lapply

years <- Reduce(intersect, lapply(c, `[[`, 'Year'))
c1 <- lapply(c, subset, subset = Year %in% years)