When I melt a data frame with some dates I am getting some strange results. I
seem to lose the date format with POSIXct and get a row of zeros with POSIXlt
Any suggestions as to what I am messing up? Code and data below.
Thanks,
John Kane
Kingston ON Canada
mydata <- structure(list(dd1 = structure(c(1325397600L, 1325401200L,
1325404800L,
1325408400L, 1325412000L, 1325415600L, 1325419200L, 1325422800L,
1325426400L, 1325430000L, 1325433600L, 1325437200L, 1325440800L,
1325444400L, 1325448000L, 1325451600L, 1325455200L, 1325458800L,
1325462400L, 1325466000L), class = c("POSIXct", "POSIXt"),
tzone = ""),
dd2 = structure(c(1325426400, 1325412000, 1325426400, 1325422800,
1325422800, 1325426400, 1325433600, 1325437200, 1325455200,
1325458800, 1325451600, 1325458800, 1325466000, 1325466000,
1325476800, 1325476800, 1325480400, 1325466000, 1325480400,
1325491200), class = c("POSIXct", "POSIXt"), tzone =
""),
emp = structure(c(1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L,
1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L), class = "factor", .Label
= c("part-time",
"self-employed")), period = 1:20), .Names = c("dd1",
"dd2",
"emp", "period"), row.names = c(NA, -20L), class =
"data.frame")
library(lubridate)
library(reshape2)
str(mydata)
mdat <- melt(mydata, id=c("emp","period"))
str(mdat)
# alternatively
mydata$dd1 <- as.POSIXlt(mydata$dd1)
mydata$dd2 <- as.POSIXlt(mydata$dd2)
str(mydata)
mdat <- melt(mydata, id=c("emp","period"))
str(mdat)
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In the first case:
?mdat$value<-.POSIXct(mdat$value,tz="EST")
?mdat$value[1:3]
#[1] "2012-01-01 01:00:00 EST" "2012-01-01 02:00:00 EST"
#[3] "2012-01-01 03:00:00 EST"
?mydata$dd1[1:3]
#[1] "2012-01-01 01:00:00 EST" "2012-01-01 02:00:00 EST"
#[3] "2012-01-01 03:00:00 EST"
A.K.
----- Original Message -----
From: John Kane <jrkrideau at inbox.com>
To: r-help at r-project.org
Cc:
Sent: Monday, May 13, 2013 1:36 PM
Subject: [R] melt in reshape2 destroying dates?
When I melt a data frame with some dates I am getting some strange results. I
seem to lose the date format with POSIXct and get a row of zeros with POSIXlt
Any suggestions as to what I am messing up? Code and data below.
Thanks,
John Kane
Kingston ON Canada
mydata? <-? structure(list(dd1 = structure(c(1325397600L, 1325401200L,
1325404800L,
1325408400L, 1325412000L, 1325415600L, 1325419200L, 1325422800L,
1325426400L, 1325430000L, 1325433600L, 1325437200L, 1325440800L,
1325444400L, 1325448000L, 1325451600L, 1325455200L, 1325458800L,
1325462400L, 1325466000L), class = c("POSIXct", "POSIXt"),
tzone = ""),
? ? dd2 = structure(c(1325426400, 1325412000, 1325426400, 1325422800,
? ? 1325422800, 1325426400, 1325433600, 1325437200, 1325455200,
? ? 1325458800, 1325451600, 1325458800, 1325466000, 1325466000,
? ? 1325476800, 1325476800, 1325480400, 1325466000, 1325480400,
? ? 1325491200), class = c("POSIXct", "POSIXt"), tzone =
""),
? ? emp = structure(c(1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L,
? ? 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L), class = "factor", .Label
= c("part-time",
? ? "self-employed")), period = 1:20), .Names = c("dd1",
"dd2",
"emp", "period"), row.names = c(NA, -20L), class =
"data.frame")
library(lubridate)
library(reshape2)
? str(mydata)
? mdat? <-? melt(mydata, id=c("emp","period"))
? str(mdat)
?
? # alternatively
?
? mydata$dd1? <-? as.POSIXlt(mydata$dd1)
? mydata$dd2? <-? as.POSIXlt(mydata$dd2)
? str(mydata)
? mdat? <-? melt(mydata, id=c("emp","period"))
? str(mdat)
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and provide commented, minimal, self-contained, reproducible code.
Thanks very much. I could have sworn I had tried that but obviously I had not. So melt() is returning the correct value which is what I had suspected but I obiously did not convert it properly.I wonder if this buggy enough to mention the behaviour to the package maintainer? John Kane Kingston ON Canada> -----Original Message----- > From: smartpink111 at yahoo.com > Sent: Mon, 13 May 2013 11:05:58 -0700 (PDT) > To: jrkrideau at inbox.com > Subject: Re: [R] melt in reshape2 destroying dates? > > In the first case: > ?mdat$value<-.POSIXct(mdat$value,tz="EST") > ?mdat$value[1:3] > #[1] "2012-01-01 01:00:00 EST" "2012-01-01 02:00:00 EST" > #[3] "2012-01-01 03:00:00 EST" > ?mydata$dd1[1:3] > #[1] "2012-01-01 01:00:00 EST" "2012-01-01 02:00:00 EST" > #[3] "2012-01-01 03:00:00 EST" > A.K. > > > > ----- Original Message ----- > From: John Kane <jrkrideau at inbox.com> > To: r-help at r-project.org > Cc: > Sent: Monday, May 13, 2013 1:36 PM > Subject: [R] melt in reshape2 destroying dates? > > When I melt a data frame with some dates I am getting some strange > results. I seem to lose the date format with POSIXct and get a row of > zeros with POSIXlt > > Any suggestions as to what I am messing up? Code and data below. > Thanks, > John Kane > Kingston ON Canada > > mydata? <-? structure(list(dd1 = structure(c(1325397600L, 1325401200L, > 1325404800L, > 1325408400L, 1325412000L, 1325415600L, 1325419200L, 1325422800L, > 1325426400L, 1325430000L, 1325433600L, 1325437200L, 1325440800L, > 1325444400L, 1325448000L, 1325451600L, 1325455200L, 1325458800L, > 1325462400L, 1325466000L), class = c("POSIXct", "POSIXt"), tzone = ""), > ? ? dd2 = structure(c(1325426400, 1325412000, 1325426400, 1325422800, > ? ? 1325422800, 1325426400, 1325433600, 1325437200, 1325455200, > ? ? 1325458800, 1325451600, 1325458800, 1325466000, 1325466000, > ? ? 1325476800, 1325476800, 1325480400, 1325466000, 1325480400, > ? ? 1325491200), class = c("POSIXct", "POSIXt"), tzone = ""), > ? ? emp = structure(c(1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, > ? ? 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L), class = "factor", .Label > c("part-time", > ? ? "self-employed")), period = 1:20), .Names = c("dd1", "dd2", > "emp", "period"), row.names = c(NA, -20L), class = "data.frame") > > library(lubridate) > library(reshape2) > > ? str(mydata) > ? mdat? <-? melt(mydata, id=c("emp","period")) > ? str(mdat) > > ? # alternatively > > ? mydata$dd1? <-? as.POSIXlt(mydata$dd1) > ? mydata$dd2? <-? as.POSIXlt(mydata$dd2) > ? str(mydata) > ? mdat? <-? melt(mydata, id=c("emp","period")) > ? str(mdat) > > ____________________________________________________________ > TRY FREE IM TOOLPACK at http://www.imtoolpack.com/default.aspx?rc=if5 > Capture screenshots, upload images, edit and send them to your friends > through IMs, post on Twitter?, Facebook?, MySpace?, LinkedIn? ? FAST! > > ______________________________________________ > 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.____________________________________________________________ FREE 3D MARINE AQUARIUM SCREENSAVER - Watch dolphins, sharks & orcas on your desktop!
Amazingly enough I think i actually understand that albeit superficially. Thanks John Kane Kingston ON Canada> -----Original Message----- > From: smartpink111 at yahoo.com > Sent: Mon, 13 May 2013 11:22:35 -0700 (PDT) > To: jrkrideau at inbox.com > Subject: Re: [R] melt in reshape2 destroying dates? > > Hi John, > No problem > > If you look at the storage mode: > storage.mode(mydata$dd1) > #[1] "integer" > > I think during melt, it > class(mdat$value) > #[1] "numeric" > ?class(mydata$dd1) > #[1] "POSIXct" "POSIXt" > I guess during melting, this gets coerced to integer class. > You can also do: > ?mdat$value<-structure(mdat$value,class=c("POSIXt","POSIXct")) > #or > as.POSIXct(mdat$value,origin="1970-01-01") > > class(mdat$value) > #[1] "POSIXt"? "POSIXct" > A.K. > > > ----- Original Message ----- > From: John Kane <jrkrideau at inbox.com> > To: arun <smartpink111 at yahoo.com> > Cc: R help <r-help at r-project.org> > Sent: Monday, May 13, 2013 2:11 PM > Subject: Re: [R] melt in reshape2 destroying dates? > > Thanks very much.? I could have sworn I had tried that but obviously I > had not. > > So melt() is returning the correct value which is what I had suspected > but I obiously did not convert it properly.I wonder if this buggy enough > to mention the behaviour to the package maintainer? > > > > John Kane > Kingston ON Canada > > >> -----Original Message----- >> From: smartpink111 at yahoo.com >> Sent: Mon, 13 May 2013 11:05:58 -0700 (PDT) >> To: jrkrideau at inbox.com >> Subject: Re: [R] melt in reshape2 destroying dates? >> >> In the first case: >> ?mdat$value<-.POSIXct(mdat$value,tz="EST") >> ?mdat$value[1:3] >> #[1] "2012-01-01 01:00:00 EST" "2012-01-01 02:00:00 EST" >> #[3] "2012-01-01 03:00:00 EST" >> ?mydata$dd1[1:3] >> #[1] "2012-01-01 01:00:00 EST" "2012-01-01 02:00:00 EST" >> #[3] "2012-01-01 03:00:00 EST" >> A.K. >> >> >> >> ----- Original Message ----- >> From: John Kane <jrkrideau at inbox.com> >> To: r-help at r-project.org >> Cc: >> Sent: Monday, May 13, 2013 1:36 PM >> Subject: [R] melt in reshape2 destroying dates? >> >> When I melt a data frame with some dates I am getting some strange >> results. I seem to lose the date format with POSIXct and get a row of >> zeros with POSIXlt >> >> Any suggestions as to what I am messing up? Code and data below. >> Thanks, >> John Kane >> Kingston ON Canada >> >> mydata? <-? structure(list(dd1 = structure(c(1325397600L, 1325401200L, >> 1325404800L, >> 1325408400L, 1325412000L, 1325415600L, 1325419200L, 1325422800L, >> 1325426400L, 1325430000L, 1325433600L, 1325437200L, 1325440800L, >> 1325444400L, 1325448000L, 1325451600L, 1325455200L, 1325458800L, >> 1325462400L, 1325466000L), class = c("POSIXct", "POSIXt"), tzone = ""), >> ? ? dd2 = structure(c(1325426400, 1325412000, 1325426400, 1325422800, >> ? ? 1325422800, 1325426400, 1325433600, 1325437200, 1325455200, >> ? ? 1325458800, 1325451600, 1325458800, 1325466000, 1325466000, >> ? ? 1325476800, 1325476800, 1325480400, 1325466000, 1325480400, >> ? ? 1325491200), class = c("POSIXct", "POSIXt"), tzone = ""), >> ? ? emp = structure(c(1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, >> ? ? 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L, 1L, 2L), class = "factor", .Label >> c("part-time", >> ? ? "self-employed")), period = 1:20), .Names = c("dd1", "dd2", >> "emp", "period"), row.names = c(NA, -20L), class = "data.frame") >> >> library(lubridate) >> library(reshape2) >> >> ? str(mydata) >> ? mdat? <-? melt(mydata, id=c("emp","period")) >> ? str(mdat) >> >> ? # alternatively >> >> ? mydata$dd1? <-? as.POSIXlt(mydata$dd1) >> ? mydata$dd2? <-? as.POSIXlt(mydata$dd2) >> ? str(mydata) >> ? mdat? <-? melt(mydata, id=c("emp","period")) >> ? str(mdat) >> >> ____________________________________________________________ >> TRY FREE IM TOOLPACK at http://www.imtoolpack.com/default.aspx?rc=if5 >> Capture screenshots, upload images, edit and send them to your friends >> through IMs, post on Twitter?, Facebook?, MySpace?, LinkedIn? ? FAST! >> >> ______________________________________________ >> 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. > > ____________________________________________________________ > FREE 3D MARINE AQUARIUM SCREENSAVER - Watch dolphins, sharks & orcas on > your desktop! > Check it out at http://www.inbox.com/marineaquarium____________________________________________________________ FREE ONLINE PHOTOSHARING - Share your photos online with your friends and family! Visit http://www.inbox.com/photosharing to find out more!