R: How to filter/subset a sequence of dates

Omar Gonzales picture Omar Gonzales · Feb 5, 2015 · Viewed 73.5k times · Source

I have this data: (complete for December)

      date     sessions
1   2014-12-01  1932
2   2014-12-02  1828
3   2014-12-03  2349
4   2014-12-04  8192
5   2014-12-05  3188
6   2014-12-06  3277

And a need to subset/filter this, for example from "2014-12-05" to "2014-12-25"

I know that you can create a sequence with the operator ":".

Example: b <- c(1:5)

But How to filter a sequence? I tried this

NewDate <- filter(Dates, date("2014-12-05":"2014-12-12"))

But says:

Error: unexpected symbol in: "NewDate <- filter(Dates, date("2014-12-05":"2014-12-12") NewDate"

Answer

jalapic picture jalapic · Feb 5, 2015

you could use subset

Generating your sample data:

temp<-
read.table(text="date     sessions
2014-12-01  1932
2014-12-02  1828
2014-12-03  2349
2014-12-04  8192
2014-12-05  3188
2014-12-06  3277", header=T)

Making sure it's in date format:

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

temp



 #        date sessions
 # 1 2014-12-01     1932
 # 2 2014-12-02     1828
 # 3 2014-12-03     2349
 # 4 2014-12-04     8192
 # 5 2014-12-05     3188
 # 6 2014-12-06     3277

Using subset :

subset(temp, date> "2014-12-03" & date < "2014-12-05")

which gives:

  #        date sessions
  # 4 2014-12-04     8192

you could also use []:

temp[(temp$date> "2014-12-03" & temp$date < "2014-12-05"),]