Re: [R] Creating xts objects from csv file
Hello,
I've cc-ed the list.
Yes, I believe that generally speaking, POSIXct is better than POSIXlt.
POSIXlt is a complicated structure, POSXct is much simpler and gives
less problems. Datetimes are a problem because they are datetimes but
POSIXct is a good way of trying to make things simpler. It's also the
class returned by packages like lubridate, functions ymd_hms and
similar. SO I think it's the prefered class for problems with datetime
variables.
Rui Barradas
Às 17:59 de 21/07/2020, Jeff Reichman escreveu:
Rui
So generally would it be better to us POSIXct than POSIXlt?
Jeff
-Original Message-
From: Rui Barradas
Sent: Tuesday, July 21, 2020 5:58 AM
To: reichm...@sbcglobal.net
Subject: Re: [R] Creating xts objects from csv file
Hello,
Why it didn't work I don't know but the opposite happens to me, I rarely use
as.POSIXlt.
This is because "POSIXlt" objects are complicated, list-like objects. Try
ct <- as.POSIXct("2020-07-21 12:30")
lt <- as.POSIXlt("2020-07-21 12:30")
attributes(ct)
unclass(ct)
attributes(lt)
unclass(lt)
POSIXlt objects can be usefull when their components are needed but many times
the problems are simple and the POSIXct class is simpler.
Rui Barradas
Às 00:40 de 21/07/2020, Jeff Reichman escreveu:
Rui
Yes that worked. I rarely if ever use the POSIXct function . Wonder why POSIXct
worded and POSIXlt didn't
JEff
-Original Message-
From: Rui Barradas
Sent: Monday, July 20, 2020 4:37 PM
To: reichm...@sbcglobal.net; r-help@r-project.org
Subject: Re: [R] Creating xts objects from csv file
Hello,
I cannot reproduce the error, your code runs as expected. Try as.POSIXct?
Hope this helps,
Rui Barradas
Às 21:32 de 20/07/2020, Jeff Reichman escreveu:
R-Help Forum
Starting to work with xts objects but can't figure out what I'm doing
wrong when converting *.csv file with a dtg variable to a *.xts
object. When I'm converting to an appropriate time object all I get
are NA, so that's my first issue.
dtg <- c("1/5/2010 2:30", "1/5/2010 10:32", "1/5/2010 12:03")
seq <- c(1,2,3)
dat <- data.frame(dtg, seq)
dat$dtg <- as.POSIXlt(dat$dtg, format = "%m/%d/%Y %H:%M")
dat.xts <- xts(x = dat[,-1], order.by = dat[,1])
head(dat.xts)
Sincerely
Jeff Reichman
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Re: [R] Creating xts objects from csv file
Please reply on-list, so others may benefit from the conversation.
I'm glad you got it working, despite not being sure what the problem
was. I agree that you should use POSIXct instead of POSIXlt. POSIXlt
are fairly large, since they're a list of 9 elements each with an
observation for each timestamp.
Here's a sample of your file (as text) and a way you can read it into
R using read.csv.zoo(). Replace the `irreg` object with your filename
(e.g. `"irreg.csv"`).
Lines <- "DTG,Seq
1/5/2010 2:30,1
1/5/2010 10:32,2
1/5/2010 12:03,3
1/6/2010 6:01,4
1/6/2010 17:55,5
1/6/2010 23:42,6
1/7/2010 1:14,7
1/7/2010 5:00,8
1/7/2010 9:40,9
1/7/2010 13:14,10
1/7/2010 13:22,11
1/7/2010 16:12,12
1/7/2010 20:10,13
1/7/2010 21:52,14
1/7/2010 22:22,15"
irreg <- textConnection(Lines)
z <- zoo::read.csv.zoo(irreg, format = "%m/%d/%Y %H:%M", tz = "", drop = FALSE)
x <- xts::as.xts(z) # if you want an xts object
On Tue, Jul 21, 2020 at 12:09 PM Jeff Reichman wrote:
>
>Joshua
>
>I tried POSIXct and it worked just fine???
>
>Then I tried modifying my code to
>
>myDat$DTG <- as.POSIXlt(myDat$DTG, format = "%m/%d/%Y %H:%M")
>irreg <- xts(x=myDat[,-1],order.by= as.POSIXct(myDat$DTG))
>
>which seemed to work, so I'm not sure what I was doing wrong. But I
> also gather I should probably use POSIXct objects as opposed to POSIXlt
> objects.
>
>Jeff
>
>
> -----Original Message-----
> From: Joshua Ulrich
> Sent: Tuesday, July 21, 2020 9:28 AM
> To: reichm...@sbcglobal.net
> Cc: R-Help
> Subject: Re: [R] Creating xts objects from csv file
>
> Your example works for me. Can you provide a sample of the CSV you're trying
> to read, and the commands you use to read it? The output of
> sessionInfo() might also be helpful.
>
>
> On Mon, Jul 20, 2020 at 3:42 PM Jeff Reichman wrote:
> >
> > R-Help Forum
> >
> >
> >
> > Starting to work with xts objects but can't figure out what I'm doing wrong
> > when converting *.csv file with a dtg variable to a *.xts object. When I'm
> > converting to an appropriate time object all I get are NA, so that's my
> > first issue.
> >
> >
> >
> > dtg <- c("1/5/2010 2:30", "1/5/2010 10:32", "1/5/2010 12:03")
> >
> > seq <- c(1,2,3)
> >
> >
> >
> > dat <- data.frame(dtg, seq)
> >
> >
> >
> > dat$dtg <- as.POSIXlt(dat$dtg, format = "%m/%d/%Y %H:%M")
> >
> >
> >
> > dat.xts <- xts(x = dat[,-1], order.by = dat[,1])
> >
> >
> >
> > head(dat.xts)
> >
> >
> >
> > Sincerely
> >
> >
> >
> > Jeff Reichman
> >
> >
> > [[alternative HTML version deleted]]
> >
> > __
> > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
>
>
>
> --
> Joshua Ulrich | about.me/joshuaulrich
> FOSS Trading | www.fosstrading.com
--
Joshua Ulrich | about.me/joshuaulrich
FOSS Trading | www.fosstrading.com
__
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Re: [R] Creating xts objects from csv file
Your example works for me. Can you provide a sample of the CSV you're
trying to read, and the commands you use to read it? The output of
sessionInfo() might also be helpful.
On Mon, Jul 20, 2020 at 3:42 PM Jeff Reichman wrote:
>
> R-Help Forum
>
>
>
> Starting to work with xts objects but can't figure out what I'm doing wrong
> when converting *.csv file with a dtg variable to a *.xts object. When I'm
> converting to an appropriate time object all I get are NA, so that's my
> first issue.
>
>
>
> dtg <- c("1/5/2010 2:30", "1/5/2010 10:32", "1/5/2010 12:03")
>
> seq <- c(1,2,3)
>
>
>
> dat <- data.frame(dtg, seq)
>
>
>
> dat$dtg <- as.POSIXlt(dat$dtg, format = "%m/%d/%Y %H:%M")
>
>
>
> dat.xts <- xts(x = dat[,-1], order.by = dat[,1])
>
>
>
> head(dat.xts)
>
>
>
> Sincerely
>
>
>
> Jeff Reichman
>
>
> [[alternative HTML version deleted]]
>
> __
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
--
Joshua Ulrich | about.me/joshuaulrich
FOSS Trading | www.fosstrading.com
__
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and provide commented, minimal, self-contained, reproducible code.
Re: [R] Creating xts objects from csv file
Are you sure you loaded the xts library?
On Mon, 20 Jul 2020 at 16:32, Jeff Reichman wrote:
> R-Help Forum
>
>
>
> Starting to work with xts objects but can't figure out what I'm doing wrong
> when converting *.csv file with a dtg variable to a *.xts object. When I'm
> converting to an appropriate time object all I get are NA, so that's my
> first issue.
>
>
>
> dtg <- c("1/5/2010 2:30", "1/5/2010 10:32", "1/5/2010 12:03")
>
> seq <- c(1,2,3)
>
>
>
> dat <- data.frame(dtg, seq)
>
>
>
> dat$dtg <- as.POSIXlt(dat$dtg, format = "%m/%d/%Y %H:%M")
>
>
>
> dat.xts <- xts(x = dat[,-1], order.by = dat[,1])
>
>
>
> head(dat.xts)
>
>
> [[alternative HTML version deleted]]
>
> __
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
--
John Kane
Kingston ON Canada
[[alternative HTML version deleted]]
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Re: [R] Creating xts objects from csv file
Might this be related to the stringsAsfactors change? -- the new default is
FALSE, the old was TRUE.
Bert Gunter
"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
On Mon, Jul 20, 2020 at 2:37 PM Rui Barradas wrote:
> Hello,
>
> I cannot reproduce the error, your code runs as expected. Try as.POSIXct?
>
> Hope this helps,
>
> Rui Barradas
>
> Às 21:32 de 20/07/2020, Jeff Reichman escreveu:
> > R-Help Forum
> >
> >
> >
> > Starting to work with xts objects but can't figure out what I'm doing
> wrong
> > when converting *.csv file with a dtg variable to a *.xts object. When
> I'm
> > converting to an appropriate time object all I get are NA, so that's my
> > first issue.
> >
> >
> >
> > dtg <- c("1/5/2010 2:30", "1/5/2010 10:32", "1/5/2010 12:03")
> >
> > seq <- c(1,2,3)
> >
> >
> >
> > dat <- data.frame(dtg, seq)
> >
> >
> >
> > dat$dtg <- as.POSIXlt(dat$dtg, format = "%m/%d/%Y %H:%M")
> >
> >
> >
> > dat.xts <- xts(x = dat[,-1], order.by = dat[,1])
> >
> >
> >
> > head(dat.xts)
> >
> >
> >
> > Sincerely
> >
> >
> >
> > Jeff Reichman
> >
> >
> > [[alternative HTML version deleted]]
> >
> > __
> > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
>
>
> --
> Este e-mail foi verificado em termos de vírus pelo software antivírus
> Avast.
> https://www.avast.com/antivirus
>
> __
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
[[alternative HTML version deleted]]
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R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] Creating xts objects from csv file
Hello,
I cannot reproduce the error, your code runs as expected. Try as.POSIXct?
Hope this helps,
Rui Barradas
Às 21:32 de 20/07/2020, Jeff Reichman escreveu:
R-Help Forum
Starting to work with xts objects but can't figure out what I'm doing wrong
when converting *.csv file with a dtg variable to a *.xts object. When I'm
converting to an appropriate time object all I get are NA, so that's my
first issue.
dtg <- c("1/5/2010 2:30", "1/5/2010 10:32", "1/5/2010 12:03")
seq <- c(1,2,3)
dat <- data.frame(dtg, seq)
dat$dtg <- as.POSIXlt(dat$dtg, format = "%m/%d/%Y %H:%M")
dat.xts <- xts(x = dat[,-1], order.by = dat[,1])
head(dat.xts)
Sincerely
Jeff Reichman
[[alternative HTML version deleted]]
__
R-help@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.
--
Este e-mail foi verificado em termos de vírus pelo software antivírus Avast.
https://www.avast.com/antivirus
__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
