use 'merge':
> DF = data.frame(X = c(114.5508, 114.6468, 114.6596, 114.6957, 114.6828,
> 114.8903, 114.9519, 114.8842,
+ 114.8579, 114.8489), Y = c(47.14094, 46.98874, 46.91235, 46.88265,
46.80584, 46.67022, 46.53264, 46.47727,
+ 46.46457, 46.47032), Date = as.Date(c('2009-01-01', '2009-01-03',
'2009-01-05', '2009-01-10', '2009-01-14',
+ '2009-01-15', '2009-01-16', '2009-01-17', '2009-01-22', '2009-01-29')))
>
> s.d1 = '2009-01-01'
> e.d1 = '2009-01-14'
> f.n1 = seq(from = as.Date(s.d1) , to = as.Date(e.d1), by = 1)
>
> s.d2 = '2009-01-15'
> e.d2 = '2009-01-31'
> f.n2 = seq(from = as.Date(s.d2) , to = as.Date(e.d2), by = 1)
> x.new <- data.frame(Date=c(f.n1, f.n2),
+ Fortnight=c(rep("FN1", length(f.n1)), rep("FN2", length(f.n2))))
>
> merge(DF, x.new, all.x=TRUE)
Date X Y Fortnight
1 2009-01-01 114.5508 47.14094 FN1
2 2009-01-03 114.6468 46.98874 FN1
3 2009-01-05 114.6596 46.91235 FN1
4 2009-01-10 114.6957 46.88265 FN1
5 2009-01-14 114.6828 46.80584 FN1
6 2009-01-15 114.8903 46.67022 FN2
7 2009-01-16 114.9519 46.53264 FN2
8 2009-01-17 114.8842 46.47727 FN2
9 2009-01-22 114.8579 46.46457 FN2
10 2009-01-29 114.8489 46.47032 FN2
On Mon, Jul 5, 2010 at 4:01 PM, Abdi, Abdulhakim <ab...@si.edu> wrote:
> Dear List,
>
> I've been looking tirelessly for a solution to this dilemma but without
> success. Perhaps someone has an idea that will guide me in the right
> direction.
>
> Suppose I have the following data.frame:
>
> DF = data.frame(X = c(114.5508, 114.6468, 114.6596, 114.6957, 114.6828,
> 114.8903, 114.9519, 114.8842,
> 114.8579, 114.8489), Y = c(47.14094, 46.98874, 46.91235, 46.88265, 46.80584,
> 46.67022, 46.53264, 46.47727,
> 46.46457, 46.47032), Date = as.Date(c('2009-01-01', '2009-01-03',
> '2009-01-05', '2009-01-10', '2009-01-14',
> '2009-01-15', '2009-01-16', '2009-01-17', '2009-01-22', '2009-01-29')))
>
> DF
> X Y Date
> 1 114.5508 47.14094 2009-01-01
> 2 114.6468 46.98874 2009-01-03
> 3 114.6596 46.91235 2009-01-05
> 4 114.6957 46.88265 2009-01-10
> 5 114.6828 46.80584 2009-01-14
> 6 114.8903 46.67022 2009-01-15
> 7 114.9519 46.53264 2009-01-16
> 8 114.8842 46.47727 2009-01-17
> 9 114.8579 46.46457 2009-01-22
> 10 114.8489 46.47032 2009-01-29
>
> I also have two objects that contain the dates of the first and last
> fortnight of the month of January 2009.
>
> s.d1 = '2009-01-01'
> e.d1 = '2009-01-14'
> f.n1 = seq(from = as.Date(s.d1) , to = as.Date(e.d1), by = 1)
>
> f.n1
> [1] "2009-01-01" "2009-01-02" "2009-01-03" "2009-01-04" "2009-01-05"
> "2009-01-06" "2009-01-07" "2009-01-08" "2009-01-09" "2009-01-10" "2009-01-11"
> "2009-01-12" "2009-01-13" "2009-01-14"
>
> s.d2 = '2009-01-15'
> e.d2 = '2009-01-31'
> f.n2 = seq(from = as.Date(s.d2) , to = as.Date(e.d2), by = 1)
>
> f.n2
> [1] "2009-01-15" "2009-01-16" "2009-01-17" "2009-01-18" "2009-01-19"
> "2009-01-20" "2009-01-21" "2009-01-22" "2009-01-23" "2009-01-24" "2009-01-25"
> "2009-01-26" "2009-01-27" "2009-01-28" "2009-01-29" "2009-01-30" "2009-01-31"
>
>
> I'm trying to add a column called "Fortnight" to the existing data.frame. The
> components of the new "Fortnight" column are based on the existing "Date"
> column so that if the value in "Date" falls within the first fortnight (f.n1)
> then the value of the new "Fortnight" column would be "FN1", and if the value
> of the "Date" column falls within the second fortnight (f.n2), then the value
> of the "Fortnight" column would be "FN2", and so on.
>
> The end result should look like:
>
> X Y Date Fortnight
> 1 114.5508 47.14094 2009-01-01 FN1
> 2 114.6468 46.98874 2009-01-03 FN1
> 3 114.6596 46.91235 2009-01-05 FN1
> 4 114.6957 46.88265 2009-01-10 FN1
> 5 114.6828 46.80584 2009-01-14 FN1
> 6 114.8903 46.67022 2009-01-15 FN2
> 7 114.9519 46.53264 2009-01-16 FN2
> 8 114.8842 46.47727 2009-01-17 FN2
> 9 114.8579 46.46457 2009-01-22 FN2
> 10 114.8489 46.47032 2009-01-29 FN2
>
> I manually entered the above values for the "Fortnight" column to illustrate
> my point, however, that would be quite tiresome for 500+ rows of data ;-)
>
> The only other similar issue I found on the list was
> https://stat.ethz.ch/pipermail/r-help/2008-February/153995.html but that
> particular problem is slightly different than what I'm trying to accomplish
> here.
>
> I appreciate your time and assistance.
>
> Thanks in advance.
>
> Regards,
>
>
> Hakim Abdi
>
>
>
> _________________________________
> Abdulhakim Abdi, M.Sc.
> Research Intern
>
> Conservation GIS/Remote Sensing Lab
> Smithsonian Conservation Biology Institute
> 1500 Remount Road
> Front Royal, VA 22630
> phone: +1 540 635 6578
> mobile: +1 747 224 7006
> fax: +1 540 635 6506 (Attn:GIS Lab)
> email: ab...@si.edu
> http://nationalzoo.si.edu/SCBI/ConservationGIS/
>
>
>
>
>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
--
Jim Holtman
Cincinnati, OH
+1 513 646 9390
What is the problem that you are trying to solve?
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
