From: Gabor Grothendieck <ggrothendieck_at_gmail.com>

Date: Sat, 26 Jul 2008 17:59:47 -0400

R-help_at_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. Received on Sat 26 Jul 2008 - 22:04:14 GMT

Date: Sat, 26 Jul 2008 17:59:47 -0400

For the last statement we may prefer this so it stays a zoo object:

*> m <- merge(Az, Bz, fill = 0)
*

> m[,1] - m[,2]

1 2 3 4 5

1429 0 3049 0 2219

On Sat, Jul 26, 2008 at 5:53 PM, Gabor Grothendieck
<ggrothendieck_at_gmail.com> wrote:

> Look at merge.zoo

*>
**>> library(zoo)
**>> dput(A)
**> structure(list(DayOfYear = 1:5, x = c(1429L, 3952L, 3049L, 2844L,
**> 2219L)), .Names = c("DayOfYear", "x"), class = "data.frame", row.names = c("1",
**> "2", "3", "4", "5"))
**>> B <- A[c(2,4),]
**>> Az <- zoo(A$x, A$DayOfYear)
**>> Bz <- zoo(B$x, B$DayOfYear)
**>> merge(Az, Bz, fill = 0)
**> Az Bz
**> 1 1429 0
**> 2 3952 3952
**> 3 3049 0
**> 4 2844 2844
**> 5 2219 0
**>> merge(Az, Bz, fill = 0) %*% c(1, -1)
**> [,1]
**> [1,] 1429
**> [2,] 0
**> [3,] 3049
**> [4,] 0
**> [5,] 2219
**>
**>
**> On Sat, Jul 26, 2008 at 5:26 PM, <rkevinburton_at_charter.net> wrote:
**>> I have two vectos (list) that represent a years of data. Each "row" is represented by the day of year and the quantity that was sold for that day. I would like to form a new vector that is the difference between the two years of data. A sample of A (and similarly B) looks like:
**>>
**>>> A[1:5,]
**>> DayOfYear x
**>> 1 1 1429
**>> 2 2 3952
**>> 3 3 3049
**>> 4 4 2844
**>> 5 5 2219
**>>>
**>>
**>> D <- A - B
**>>
**>> This works just fine if A and B are both the same length. How is the best way to handle the situation where A and B are of different lengths? If the day of year exists in both vectors (lists) then I just want the coorespondng "row" in D to be the difference btween A and B values. If the "row" doesn't exist in either A or B then the difference should be treated as if the missing "row" was zero. Is this feasible?
**>>
**>> Thank you.
**>>
**>> Kevin
**>>
**>> ______________________________________________
**>> R-help_at_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.
**>>
**>
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R-help_at_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. Received on Sat 26 Jul 2008 - 22:04:14 GMT

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