Hi I have a matrix that contains 1565 rows and 132 columns. All the observations are either "0" or "1". Now I want to keep all the observations same but just one change, i.e. whenever there is "1", the very next value in the same row should become "1". Please see below as a sample:>df0 0 1 0 0 NA 0 1 1 0 0 1 0 0 NA What I want is: 0 0 1 1 0 NA 0 1 1 1 0 1 1 0 NA I shall be thankful for the reply. Saba
tmpf <- function(x) {
n <- length(x)
indices <- which(match(x,1) == 1)
x[indices+1] <- 1
x[1:n] ## needed for the case when the last item in a row has value 1
}
tmp <- matrix(c(0,0,1,0,0,
NA,0,1,1,0,
0,1,0,0,NA,
1,0,1,0,1), ## last item in row has value 1
byrow=TRUE, 4, 5)
tmp
t(apply(tmp, 1, tmpf))
On Thu, Sep 22, 2016 at 10:27 PM, Saba Sehrish via R-help
<r-help at r-project.org> wrote:> Hi
>
> I have a matrix that contains 1565 rows and 132 columns. All the
observations are either "0" or "1". Now I want to keep all
the observations same but just one change, i.e. whenever there is "1",
the very next value in the same row should become "1". Please see
below as a sample:
>
>>df
>
> 0 0 1 0 0
> NA 0 1 1 0
> 0 1 0 0 NA
>
> What I want is:
>
>
> 0 0 1 1 0
> NA 0 1 1 1
> 0 1 1 0 NA
>
>
>
> I shall be thankful for the reply.
>
>
> Saba
>
> ______________________________________________
> R-help at 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.
Hi Saba, Try this: df<-matrix(c(0,NA,0,0,0,1,1,1,0,0,1,0,0,0,NA),nrow=3) dimdf<-dim(df) df1<-df==1 df[cbind(rep(FALSE,dimdf[1]),df1[,-dimdf[2]])]<-1 Jim On Fri, Sep 23, 2016 at 12:27 PM, Saba Sehrish via R-help <r-help at r-project.org> wrote:> Hi > > I have a matrix that contains 1565 rows and 132 columns. All the observations are either "0" or "1". Now I want to keep all the observations same but just one change, i.e. whenever there is "1", the very next value in the same row should become "1". Please see below as a sample: > >>df > > 0 0 1 0 0 > NA 0 1 1 0 > 0 1 0 0 NA > > What I want is: > > > 0 0 1 1 0 > NA 0 1 1 1 > 0 1 1 0 NA > > > > I shall be thankful for the reply. > > > Saba > > ______________________________________________ > R-help at 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.
which(df == 1, arr.ind=TRUE) is useful here:> df <- matrix(c(0,NA,0,0,0,1,1,1,0,0,1,0,0,0,NA), nrow=3) > df[,1] [,2] [,3] [,4] [,5] [1,] 0 0 1 0 0 [2,] NA 0 1 1 0 [3,] 0 1 0 0 NA> ## Identify (row,col) indices for 1:s > idxs <- which(df == 1, arr.ind=TRUE) > idxsrow col [1,] 3 2 [2,] 1 3 [3,] 2 3 [4,] 2 4> ## Drop any in the last column > idxs <- idxs[idxs[,"col"] < ncol(df), , drop=FALSE] > idxsrow col [1,] 3 2 [2,] 1 3 [3,] 2 3 [4,] 2 4> idxs[,"col"] <- idxs[,"col"] + 1L > idxsrow col [1,] 3 3 [2,] 1 4 [3,] 2 4 [4,] 2 5> df[idxs] <- 1 > df[,1] [,2] [,3] [,4] [,5] [1,] 0 0 1 1 0 [2,] NA 0 1 1 1 [3,] 0 1 1 0 NA /Henrik On Thu, Sep 22, 2016 at 8:13 PM, Jim Lemon <drjimlemon at gmail.com> wrote:> Hi Saba, > Try this: > > df<-matrix(c(0,NA,0,0,0,1,1,1,0,0,1,0,0,0,NA),nrow=3) > dimdf<-dim(df) > df1<-df==1 > df[cbind(rep(FALSE,dimdf[1]),df1[,-dimdf[2]])]<-1 > > Jim > > > > On Fri, Sep 23, 2016 at 12:27 PM, Saba Sehrish via R-help > <r-help at r-project.org> wrote: >> Hi >> >> I have a matrix that contains 1565 rows and 132 columns. All the observations are either "0" or "1". Now I want to keep all the observations same but just one change, i.e. whenever there is "1", the very next value in the same row should become "1". Please see below as a sample: >> >>>df >> >> 0 0 1 0 0 >> NA 0 1 1 0 >> 0 1 0 0 NA >> >> What I want is: >> >> >> 0 0 1 1 0 >> NA 0 1 1 1 >> 0 1 1 0 NA >> >> >> >> I shall be thankful for the reply. >> >> >> Saba >> >> ______________________________________________ >> R-help at 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. > > ______________________________________________ > R-help at 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.