how to slice a zoo object
On Mon, Jan 24, 2011 at 4:51 AM, Blair Sutton <blairuk at gmail.com> wrote:
Hi Would anyone have any pointers on how to slice up a large zoo table. I have the following structure: -
str(ZOO_OBJ)
?zoo [1:632, 1:83] 30.4 30.4 30.4 30.4 30.3 ... ?- attr(*, "dimnames")=List of 2 ??..$ : NULL ??..$ : chr [1:83] "COL1" "COL2" "COL3" "COL4" ... ?- attr(*, "index")= POSIXct[1:632], format: "2009-05-01 01:00:00" "2009-05-02 01:00:00" ... and I would just like to take only arbitrary columns, i.e. another zoo object with only the columns "COL2", "COL5", etc.. I've tried various syntactical combinations such as those for data.frames and also tried manipulating the coredata(). What would be nice would be the ability to do this by column names and not their indexes. Any help appreciated and thanks in advance,
It works the same as matrices:
library(zoo)
z <- zoo(cbind(A = 1:4, B = 5:8, C = 9:12))
z[, c("A", "C")]
A C 1 1 9 2 2 10 3 3 11
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