Thanks Gabor for pointing in the right direction. Looked up cycle and the doc is tough to understand " cycle gives the positions in the cycle of each observation." ... how is cycle defined.
I just extended your idea to make it readable for an avg. user in the following way mRet[format(index(mRet),"%m")==11] -----Original Message----- From: Gabor Grothendieck [mailto:ggrothendi...@gmail.com] Sent: 05 November 2010 20:59 To: Santosh Srinivas Cc: r-help@r-project.org Subject: Re: [R] Extracting data only for particular index values from a zoo structure On Fri, Nov 5, 2010 at 11:21 AM, Santosh Srinivas <santosh.srini...@gmail.com> wrote: > Hello All, > > I have a zoo structure as follows: >> dput(tMRet) > structure(c(0.00138742474397713, -0.0309023681475112, 0.0390276302410908, > 0.0832282874685357, -0.00315002033871414, -0.0158548785709138, > -0.0410876001496389, -0.0503189291168807, 0.00229628598547049, > 0.112348434473647, 0.0760004696254608, 0.100820586425124, > 0.0803767768546975, > 0.0967805566974766, 0.054288018745434, 0.106415042990242, > 0.0848339767191362, > -0.0293833917022324, -0.0355384394730908, 0.0398272106900921), .Dim = c(20L, > > 1L), .Dimnames = list(c("Sep 2002", "Oct 2002", "Nov 2002", "Dec 2002", > "Jan 2003", "Feb 2003", "Mar 2003", "Apr 2003", "May 2003", "Jun 2003", > "Jul 2003", "Aug 2003", "Sep 2003", "Oct 2003", "Nov 2003", "Dec 2003", > "Jan 2004", "Feb 2004", "Mar 2004", "Apr 2004"), "Close"), index = > structure(c(2002.66666666667, > 2002.75, 2002.83333333333, 2002.91666666667, 2003, 2003.08333333333, > 2003.16666666667, 2003.25, 2003.33333333333, 2003.41666666667, > 2003.5, 2003.58333333333, 2003.66666666667, 2003.75, 2003.83333333333, > 2003.91666666667, 2004, 2004.08333333333, 2004.16666666667, 2004.25 > ), class = "yearmon"), class = "zoo") > > I want to extract only the values for say "November" but may span multiple > years. > How can I use conditions on the zoo index? > Try this: > tMRet[cycle(tMRet) == 11,, drop = FALSE] Close Nov 2002 0.03902763 Nov 2003 0.05428802 If you just want a 1 dimensional object omit the drop=FALSE part. -- Statistics & Software Consulting GKX Group, GKX Associates Inc. tel: 1-877-GKX-GROUP email: ggrothendieck at gmail.com ______________________________________________ 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.
