[R] Choosing specific Date Range from non-sequential Date

[William Dunlap]

To get a quick answer to your question you should provide a smallexample
that one can simply copy and paste into an R session.  It also helps to
show some details about how something does not work, more than " But it
didn't work."   E.g.,

d <- read.table(header=FALSE, text="1997-11-23 -2.91709629064653
1997-12-07 -0.960255426066815
1997-12-11 -1.98210752999868
1997-12-20 -1.10800598439855
1998-01-01 -1.00090115428118
1998-01-29 -1.03056081882709")
names(d) <- c("date", "measurement")
subset(d, date > "1997-12-15" & date < "1998-01-16")

which gave:

[1] date        measurement
<0 rows> (or 0-length row.names)
Warning messages:
1: In Ops.factor(date, "1997-12-15") : ‘>’ not meaningful for factors
2: In Ops.factor(date, "1998-01-16") : ‘<’ not meaningful for factors

People seeing the call to read.table() and the warning messages from
subset() could quickly and confidently recommend adding
the colClasses=c("Date", "numeric") to the call to read.table.  Without
that information, both questioners and helpers become frustrated.

Bill Dunlap
TIBCO Software
wdunlap tibco.com


On Mon, Sep 9, 2019 at 12:15 PM Ogbos Okike <giftedlife2014 using gmail.com>
wrote:

> Dear Bert and Jeff,
> Thank you for looking at this.
> I am surprised my message was not in plain text. It has been
> configured to send message to the list in plain text earlier before.
>
> The data again please.
>
> 1997-11-23 -2.91709629064653
> 1997-12-07 -0.960255426066815
> 1997-12-11 -1.98210752999868
> 1997-12-20 -1.10800598439855
> 1998-01-01 -1.00090115428118
> 1998-01-29 -1.03056081882709
> 1998-03-27 -0.873243859498216
> 1998-04-09 -2.06378384750109
> 1998-04-12 -2.06826431469008
> 1998-04-19 -2.49834620746286
> 1998-05-02 -6.4357083781542
> 1998-05-17 -2.25359807972754
> 1998-05-21 -2.55799006865995
> 1999-08-22 -2.25114162617707
> 1999-08-25 -1.47905397376409
> 1999-09-05 -0.641589808755325
> 1999-09-09 -0.648954682695949
> 1999-09-13 -0.726364489272492
> 1999-09-16 -1.28445236942011
>
> The first column is  date and the second is another data of interest.
>
> The date is long but note sequential. Runs randomly from 1953 to 2019.
>
> I would like to select any range of date from year A to year B.
>
> Thank you again for your help.
> Best
> Ogbos
>
>
> On Mon, Sep 9, 2019 at 6:18 PM Jeff Newmiller <jdnewmil using dcn.davis.ca.us>
> wrote:
> >
> > Or the column is not named "date", or it is a factor... and the question
> is not posted in plain text....
> >
> > On September 9, 2019 9:55:48 AM PDT, Bert Gunter <bgunter.4567 using gmail.com>
> wrote:
> > >I would guess that you first need to convert your textual dates to a
> > >date-time object via as.date, but as you failed to provide a
> > >reproducible
> > >example (e.g. via dput) I may be wrong. Maybe others may have greater
> > >insight.
> > >
> > >Bert Gunter
> > >
> > >"The trouble with having an open mind is that people keep coming along
> > >and
> > >sticking things into it."
> > >-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
> > >
> > >
> > >On Mon, Sep 9, 2019 at 8:55 AM Ogbos Okike <giftedlife2014 using gmail.com>
> > >wrote:
> > >
> > >> Dear Contributors,
> > >> I have a data frame of the form:
> > >> 1997-11-23 -2.91709629064653
> > >> 1997-12-07 -0.960255426066815
> > >> 1997-12-11 -1.98210752999868
> > >> 1997-12-20 -1.10800598439855
> > >> 1998-01-01 -1.00090115428118
> > >> 1998-01-29 -1.03056081882709
> > >> 1998-03-27 -0.873243859498216
> > >> 1998-04-09 -2.06378384750109
> > >> 1998-04-12 -2.06826431469008
> > >> 1998-04-19 -2.49834620746286
> > >> 1998-05-02 -6.4357083781542
> > >> 1998-05-17 -2.25359807972754
> > >> 1998-05-21 -2.55799006865995
> > >> 1999-08-22 -2.25114162617707
> > >> 1999-08-25 -1.47905397376409
> > >> 1999-09-05 -0.641589808755325
> > >> 1999-09-09 -0.648954682695949
> > >> 1999-09-13 -0.726364489272492
> > >> 1999-09-16 -1.28445236942011
> > >>
> > >> The events happen randomly and so the date is non-sequential. It run
> > >form
> > >> 1953 to 2019.
> > >>
> > >> I would like to select all the events/dates between 1998 to 2005.
> > >>
> > >> One of the things I tried is:
> > >> Year <- subset(MOSCFD50, date > "1998-01-01" & date < "2005-12-31").
> > >>
> > >> But it didn't work.
> > >>
> > >> I would be thankful if you could please redirect me.
> > >>
> > >> Thank you very much.
> > >> Best regards
> > >> Ogbos
> > >>
> > >>         [[alternative HTML version deleted]]
> > >>
> > >> ______________________________________________
> > >> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > >> 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.
> > >>
> > >
> > >       [[alternative HTML version deleted]]
> > >
> > >______________________________________________
> > >R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > >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.
> >
> > --
> > Sent from my phone. Please excuse my brevity.
>
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>

	[[alternative HTML version deleted]]