?as.POSIXct for time-formatting. This function makes a structured list of
time data, where you specify an input time and format i.e.
as.POSIXct('2014-01-09 01:30:00', format='%Y-%m-%d %H:%M:%S')
On 1/10/14, 15:24 , "Santosh" <santosh2...@gmail.com> wrote:
I don't think apropos or indexing would help. I am open to your
suggestions/tips.
I usually get multiple versions of a dataset (even with the same column
names). In the source data, I occasionally notice inconsistencies...
formatting issues, column naming issues etc..
As shown In the "a1" example,.. the values that are supposed to be in
column "Qr" are sometimes in column "b". Such differences between versions
crop up due to various unknown reasons, e.g. when different programmers
prepare the data set or if the existing practices/processes change.
Likewise, formats of certain date-time columns (not shown in the example)
also vary, the time date format may be in "%m/%d/%Y %H:%M", "%d %b %Y
%H:%M" or "%d%b%Y %H:%M"
So, I would like use programming methods to pick the right one if available
or don't pick at all.
Besides, is there an R equivalent of "%m[/][.]%d[/][,]%y
[%H[:%M[:%S[.%N]]][%p][[(]%3Z[)]]]" available in Splus (?class.timeDate)
for tackling time-date format inconsistencies as mentioned above.
Thanks,
Santosh
On Fri, Jan 10, 2014 at 2:32 PM, Bert Gunter <gunter.ber...@gene.com>
wrote:
> Don's response seems apropos to me. Do you understanding indexing,
> i.e. the "[" operator? If not, you should read An Introduction to R or
> other tutorial (there are many good ones on the web). If that is not
> the issue, you need to explain more clearly why his answer does not
> suffice.
>
> Cheers,
> Bert
>
> Bert Gunter
> Genentech Nonclinical Biostatistics
> (650) 467-7374
>
> "Data is not information. Information is not knowledge. And knowledge
> is certainly not wisdom."
> H. Gilbert Welch
>
>
>
>
> On Fri, Jan 10, 2014 at 1:59 PM, Santosh <santosh2...@gmail.com> wrote:
> > My intention is to include certain columns if they meet certain
>criteria.
> > For example, if "b" is one of the columns of a1, then keep otherwise
> don't.
> >
> > HTH..
> > santosh
> >
> >
> > On Fri, Jan 10, 2014 at 1:01 PM, MacQueen, Don <macque...@llnl.gov>
> wrote:
> >
> >> Apologies, but all that ifelse() stuff is too hard to follow.
> >>
> >> What I would do is compute a character vector of column names to keep,
> >> then do
> >>
> >> a1[ , names.to.keep]
> >>
> >> -Don
> >>
> >> --
> >> Don MacQueen
> >>
> >> Lawrence Livermore National Laboratory
> >> 7000 East Ave., L-627
> >> Livermore, CA 94550
> >> 925-423-1062
> >>
> >>
> >>
> >>
> >>
> >> On 1/10/14 12:53 PM, "Santosh" <santosh2...@gmail.com> wrote:
> >>
> >> >Dear Rxperts...
> >> >
> >> >I would like to conditionally include an element (as a column) in a
> >> >dataframe. Please see the sample code below:
> >> >
> >> >There is a correction to the earlier post.. my apologies...
> >> >a1 <- data.frame(P=rep(1,10),Qr=LETTERS[1:10],b=letters[1:10],
> >> >R=rep(c("A","B"),each=5))
> >> >
> >> > lc1 <- list(C1 = "P",C2 =
> >>
>
>>ifelse(is.element("Q",names(a1)),"Q",ifelse(is.element("b",names(a1)),"b"
>>,
> >> >NULL)),C3="R")
> >> > lc2 <- list(C1 = "P",C2 =
> >>
>
>>ifelse(is.element("Q",names(a1)),"Q",ifelse(is.element("b",names(a1)),"b"
>>,
> >> >NULL)),
> >> >C3=ifelse(is.element("Ra",names(a1)),"Ra",NULL))
> >> >*The error for the above:*
> >> >Error in ifelse(is.element("Ra", names(a1)), "Ra", NULL) :
> >> > replacement has length zero
> >> >In addition: Warning message:
> >> >In rep(no, length.out = length(ans)) :
> >> > 'x' is NULL so the result will be NULL
> >> >
> >> >a2 <- subset(a1, sel=unlist(lc1)) # this works
> >> >a3 <- subset(a1, sel=unlist(lc2)) # this doesn't work
> >> >
> >> >Is there a way to dynamically include columns in a dataframe?
> >> >
> >> >Regards,
> >> >santosh
> >> >
> >> >
> >> >On Fri, Jan 10, 2014 at 12:45 PM, Santosh <santosh2...@gmail.com>
> wrote:
> >> >
> >> >> Dear Rxperts...
> >> >>
> >> >> I would like to conditionally include an element (as a column) in a
> >> >> dataframe. Please see the sample code below:
> >> >>
> >> >> a1 <-
> >> >>
> >>
>
>>>data.frame(P=rep(1,10),Qr=LETTERS[1:10],b=letters[1:10],R=rep(c("A","B")
>>>,
> >> >>each=5))
> >> >>
> >> >> lc1 <- list(C1 = "P",C2 =
> >> >>
> >>
>
>>>ifelse(is.element("Q",names(a1)),"Q",ifelse(is.element("b",names(a1)),"b
>>>"
> >> >>,NULL)),C3="R")
> >> >> lc2 <- list(C1 = "P",C2 =
> >> >>
> >>
>
>>>ifelse(is.element("Q",names(a1)),"Q",ifelse(is.element("b",names(a1)),"b
>>>"
> >> >>,NULL)),C3="Ra")
> >> >>
> >> >> a2 <- subset(a1, sel=unlist(lc1)) # this works
> >> >> a3 <- subset(a1, sel=unlist(lc2)) # this doesn't
> >> >>
> >> >> Is there a way to dynamically include columns in a dataframe?
> >> >>
> >> >> Regards,
> >> >> santosh
> >> >>
> >> >
> >> > [[alternative HTML version deleted]]
> >> >
> >> >______________________________________________
> >> >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.
> >>
> >>
> >
> > [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > 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.
>
[[alternative HTML version deleted]]
______________________________________________
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.
The information transmitted in this email is intended on...{{dropped:8}}
______________________________________________
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.
