# [R] Help with selection of continuous data

Jim Lemon drj|m|emon @end|ng |rom gm@||@com
Mon Jun 21 12:10:41 CEST 2021

```Hi Andre,
I've taken a different approach to that employed by Eric:

A<-data.frame(c("01/01/2020","01/01/2020","01/01/2020","01/01/2020","01/01/2020",
"01/01/2020","01/01/2020","01/01/2020","01/01/2020","01/01/2020","01/01/2020",
"01/01/2020","01/02/2020","01/02/2020","01/02/2020","01/02/2020","01/03/2020",
"01/03/2020","01/03/2020","01/03/2020","01/03/2020","01/03/2020","01/03/2020",
"01/04/2020","01/04/2020","01/04/2020","01/04/2020","01/04/2020",
"01/04/2020","01/04/2020","01/04/2020","01/04/2020"),
c(23,22,12,24,26,19,34,15,17,19,23,33,23,34,25,23,25,24,34,33,31,32,24,22,21,
23,22,22,21,23,23,21),
c(13,11,12,9,8,9,7,10,11,9,6,11,9,8,9,10,11,12,9,8,10,4,6,9,8,9,10,11,14,12,
13,11),
c(1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,1,2,
3,4,5,6,7,1,2,3,4,5,6,7,8,9))
colnames(A) <- c("Date", "CO2", "CH4", "ID")
# add a variable to compile selected rows
A\$select<-FALSE
# get all unique dates
alldates<-unique(A\$Date)
for(date in alldates) {
# get indices for this date
date_indices<-which(A\$Date == date)
# only mark the first 8 as TRUE
A\$select[date_indices[1:8]]<-all(1:8 %in% A\$ID[date_indices])
}
A
A[A\$select,]

If you don't want to add a column you can set up "select" as a vector.

Jim

On Mon, Jun 21, 2021 at 6:18 PM Eric Berger <ericjberger using gmail.com> wrote:
>
> Hi André,
> It's not 100% clear to me what you are asking. I am interpreting the
> question as selecting the data from those dates for which all of
> 1,2,3,4,5,6,7,8 appear in the ID column.
> My approach determines the dates satisfying this property, which I put into
> a vector dtV. Then I take the rows of A for which the date is in the vector
> dtV.
>
> library(dplyr)
> dtV <- A %>% mutate(x=2^(ID-1)) %>% group_by(Date) %>%
> summarise(y=(sum(unique(x))%%256==255)) %>% filter(y==TRUE) %>% select(Date)
> B <- A[ A\$Date %in% dtV\$Date, ]
>
> B is the subset of A that you want.
>
> HTH,
> Eric
>
>
>
> On Mon, Jun 21, 2021 at 10:23 AM André Luis Neves <andrluis using ualberta.ca>
> wrote:
>
> > Dear R users,
> >
> > I want to select only the data containing a continuous number of *ID* from
> > 1-8 in each *DATE*. Note, I do not want to select data that do not contain
> > a continuous number in *ID *from 1-8 (eg. Data on *DATE* 1/2/2020, and
> > 01/03/2020). The dataset is a huge matrix with 24 columns and 1.5 million
> > rows, but I have prepared a reproducible code for your reference below.
> >
> > Here it is the reproducible code:
> >
> > A =
> >
> > data.frame(c("01/01/2020","01/01/2020","01/01/2020","01/01/2020","01/01/2020","01/01/2020","01/01/2020",
> >
> >
> >  "01/01/2020","01/01/2020","01/01/2020","01/01/2020","01/01/2020","01/02/2020","01/02/2020",
> >
> >
> >  "01/02/2020","01/02/2020","01/03/2020","01/03/2020","01/03/2020","01/03/2020","01/03/2020",
> >
> >
> >  "01/03/2020","01/03/2020","01/04/2020","01/04/2020","01/04/2020","01/04/2020","01/04/2020",
> >                "01/04/2020","01/04/2020","01/04/2020","01/04/2020"),
> > c(23,22,12,24,26,19,34,15,17,19,23,33,
> >
> >  23,34,25,23,25,24,34,33,31,32,24,22,21,23,22,22,21,23,23,21),
> > c(13,11,12,9,8,9,7,10,11,9,6,11,
> >                9,8,9,10,11,12,9,8,10,4,6,9,8,9,10,11,14,12,13,11),
> > c(1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,1,2,
> >                3,4,5,6,7,1,2,3,4,5,6,7,8,9))
> > colnames(A) <- c("Date", "CO2", "CH4", "ID")
> > A
> >
> > Thank you,
> > --
> > Andre
> >
> >         [[alternative HTML version deleted]]
> >
> > ______________________________________________
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> > http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
>
>         [[alternative HTML version deleted]]
>
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