On 2015/1/5 17:28, Ben Bolker wrote:> Jinsong Zhao <jszhao <at> yeah.net> writes: > > >> In the following code snippet, >> # >> a <- strptime("121114 0510", "%m%d%y %H%M") >> b <- data.frame(date = a, res = 1:5) >> class(a) >> class(b[1,1]) >> # >> I am wondering why the class of a and b[1,1] are not the same. >> >> How to make the class of a and b[1,1] to be same? > > How about > > a <- as.POSIXct(strptime(...)) > > ? (See ?POSIXct)Thanks a lot. I have used as.POSIXct(...). I am wondering why the class of a and b[1,1] are not the same. Best, Jinsong
On Jan 5, 2015, at 5:47 PM, Jinsong Zhao wrote:> On 2015/1/5 17:28, Ben Bolker wrote: >> Jinsong Zhao <jszhao <at> yeah.net> writes: >> >> >>> In the following code snippet, >>> # >>> a <- strptime("121114 0510", "%m%d%y %H%M") >>> b <- data.frame(date = a, res = 1:5) >>> class(a) >>> class(b[1,1]) >>> # >>> I am wondering why the class of a and b[1,1] are not the same. >>> >>> How to make the class of a and b[1,1] to be same? >> >> How about >> >> a <- as.POSIXct(strptime(...)) >> >> ? (See ?POSIXct) > > Thanks a lot. > > I have used as.POSIXct(...).You may have "used" it, but you don't show any code. I can think of several ways you could have _thought_ you "used it" but failed to make any changes to the underlying objects. For instance you could have executed this code: as.POSIXct(a) Which would produce console output but have no effect on 'a'.> I am wondering why the class of a and b[1,1] are not the same.We are wondering as well. What did you do? -- David Winsemius Alameda, CA, USA
On 2015/1/5 20:51, David Winsemius wrote:> > On Jan 5, 2015, at 5:47 PM, Jinsong Zhao wrote: > >> On 2015/1/5 17:28, Ben Bolker wrote: >>> Jinsong Zhao <jszhao <at> yeah.net> writes: >>> >>> >>>> In the following code snippet, >>>> # >>>> a <- strptime("121114 0510", "%m%d%y %H%M") >>>> b <- data.frame(date = a, res = 1:5) >>>> class(a) >>>> class(b[1,1]) >>>> # >>>> I am wondering why the class of a and b[1,1] are not the same. >>>> >>>> How to make the class of a and b[1,1] to be same? >>> >>> How about >>> >>> a <- as.POSIXct(strptime(...)) >>> >>> ? (See ?POSIXct) >> >> Thanks a lot. >> >> I have used as.POSIXct(...). > > You may have "used" it, but you don't show any code. I can think of several ways you could have _thought_ you "used it" but failed to make any changes to the underlying objects. For instance you could have executed this code: > > as.POSIXct(a) > > Which would produce console output but have no effect on 'a'. > > >> I am wondering why the class of a and b[1,1] are not the same. > > We are wondering as well. What did you do? > >I am very sorry for the misleading of my reply. I wanted to say that I have used the as.POSIXct(...) in my code, and it give the same output for class(a) and class(b[1,1]), as in the following code: a <- as.POSIXct(strptime("121114 0510", "%m%d%y %H%M")) aa <- strptime("121114 0510", "%m%d%y %H%M") b <- data.frame(date = aa, res = 1:5) What I am wondering is why class(aa) is different with class(b[1,1]). Best, Jinsong