karengrace84
2012-Jan-30 17:16 UTC
[R] how to sum multiple data entries for the same sampling event?
I'm having trouble with some catch per unit effort data (CPUE, fisheries data). Some of the samples were "retained" and some "unretained," and they are entered as 2 separate entries for the same sampling event (Date and time). I want to calculate the total CPUE (so sum the "retained" and "unretained" number for each sampling event) and am having troubld doing so. Here's a sample of what my data.frame looks like now: Date lmb.cpue Disposition.of.Catch 1999-07-10 12:10:00 0.66666667 Unretained 1999-07-10 12:10:00 0.16666667 Retained 1999-07-14 11:22:00 0.83333333 Unretained 1999-07-14 11:22:00 0.55555556 Retained 1999-07-14 11:48:00 0.16666667 Unretained 1999-07-14 11:48:00 0.58333333 Retained 1999-07-14 13:56:00 0.57142857 Retained 1999-07-15 10:23:00 0.11111111 Retained 1999-07-22 12:03:00 0.33333333 Retained 1999-07-25 11:26:00 0.40000000 Unretained 1999-07-25 11:26:00 1.00000000 Retained And I would like to end up with: Date lmb.cpue 1999-07-10 12:10:00 0.83333333 1999-07-14 11:22:00 1.38888889 1999-07-14 11:48:00 0.75000000 1999-07-14 13:56:00 0.57142857 1999-07-15 10:23:00 0.11111111 1999-07-22 12:03:00 0.33333333 1999-07-25 11:26:00 1.40000000 Thanks for any help you have to offer! -- View this message in context: http://r.789695.n4.nabble.com/how-to-sum-multiple-data-entries-for-the-same-sampling-event-tp4341670p4341670.html Sent from the R help mailing list archive at Nabble.com.
R. Michael Weylandt
2012-Jan-30 18:53 UTC
[R] how to sum multiple data entries for the same sampling event?
Perhaps something like
# Untested
library(plyr)
ddply(DATA, "Date", function(d) sum(d$lmb.cpue))
For example, on some fake data
DATA <- data.frame(class = rep(letters[1:5], each = 2), type
rep(c("good", "bad"), 5), value = rnorm(10))
ddply(DATA, "class", function(d) sum(d$value))
If you want to send example data, it's best to send it with the
plaintext output of dput().
Michael
On Mon, Jan 30, 2012 at 12:16 PM, karengrace84 <kgfisher at
alumni.unc.edu> wrote:> I'm having trouble with some catch per unit effort data (CPUE,
fisheries
> data). Some of the samples were "retained" and some
"unretained," and they
> are entered as 2 separate entries for the same sampling event (Date and
> time). I want to calculate the total CPUE (so sum the "retained"
and
> "unretained" number for each sampling event) and am having
troubld doing so.
> Here's a sample of what my data.frame looks like now:
>
> Date ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? lmb.cpue
> Disposition.of.Catch
> 1999-07-10 12:10:00 ? 0.66666667 ? ? ? ? ? Unretained
> 1999-07-10 12:10:00 ? 0.16666667 ? ? ? ? ? ? Retained
> 1999-07-14 11:22:00 ? 0.83333333 ? ? ? ? ? Unretained
> 1999-07-14 11:22:00 ? 0.55555556 ? ? ? ? ? ? Retained
> 1999-07-14 11:48:00 ? 0.16666667 ? ? ? ? ? Unretained
> 1999-07-14 11:48:00 ? 0.58333333 ? ? ? ? ? ? Retained
> 1999-07-14 13:56:00 ? 0.57142857 ? ? ? ? ? ? Retained
> 1999-07-15 10:23:00 ? 0.11111111 ? ? ? ? ? ? Retained
> 1999-07-22 12:03:00 ? 0.33333333 ? ? ? ? ? ? Retained
> 1999-07-25 11:26:00 ? 0.40000000 ? ? ? ? ? Unretained
> 1999-07-25 11:26:00 ? 1.00000000 ? ? ? ? ? ? Retained
>
>
> And I would like to end up with:
>
> Date ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? lmb.cpue
> 1999-07-10 12:10:00 ? 0.83333333
> 1999-07-14 11:22:00 ? 1.38888889
> 1999-07-14 11:48:00 ? 0.75000000
> 1999-07-14 13:56:00 ? 0.57142857
> 1999-07-15 10:23:00 ? 0.11111111
> 1999-07-22 12:03:00 ? 0.33333333
> 1999-07-25 11:26:00 ? 1.40000000
>
> Thanks for any help you have to offer!
>
> --
> View this message in context:
http://r.789695.n4.nabble.com/how-to-sum-multiple-data-entries-for-the-same-sampling-event-tp4341670p4341670.html
> Sent from the R help mailing list archive at Nabble.com.
>
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