Dear r genii, I hope you can help. I have vector 'b': b=c((1:10),sort(1:9,decreasing=TRUE),(2:12),sort(6:11,decreasing=TRUE),(7:13)) and, from 'b' I wish to create vector 'c': c=c( NA,NA,NA,NA,NA,NA,1,1,1,1,1,1,1,NA,NA,NA,NA,NA,NA,NA,NA,NA,NA,NA,2,2,2,2,2,2,2,2,2,2,2,NA,3,3,3,3,3,3,3) The rules I want to use to create 'c' are: A numeric of equal to, or over 7 in 'b' needs to result in a numeric (i.e. not NA) in 'c'; A numeric of less than 7 in 'b' needs to result in "NA" in 'c'; Where 'groups' of numerics equal to, or over 7 in 'b' are present (i.e. next to each other in the list), the numerics produced in 'c' all need to be the same; Each 'group' of numerics in 'b' must result in a unique numeric in 'c' (and, ideally, they should run in sequence as in 'c' above (1,2,3...). If anyone has any idea where to start on this or can crack it I'll be most grateful!! Many thanks in advance, Ben Gillespie, Research Postgraduate o-------------------------------------------------------------------o School of Geography, University of Leeds, Leeds, LS2 9JT o-------------------------------------------------------------------o Tel: +44(0)113 34 33345 Mob: +44(0)770 868 7641 o-------------------------------o http://www.geog.leeds.ac.uk/ o-------------------------------------o @RiversBenG o--------------o
Hi,
Try:
b1<- b
b1[!b1>=7]<- NA
lst1 <- split(b1,cumsum(c(0,abs(diff(b>=7)))))
?indx <- as.logical(((seq_along(lst1)-1)%%2))
lst1[indx]<- lapply(seq_along(lst1[indx]),function(i) {lst1[indx][[i]]<-
rep(i,length(lst1[indx][[i]]))})
?C2 <- unlist(lst1,use.names=FALSE)
?all.equal(c1,C2)
#[1] TRUE
A.K.
----- Original Message -----
From: arun <smartpink111 at yahoo.com>
To: Benjamin Gillespie <gybrg at leeds.ac.uk>
Cc:
Sent: Wednesday, October 9, 2013 8:19 PM
Subject: Re: [R] Possible loop/ if statement query
Hi,
There should be a simpler way with cumsum(diff()).
b=c((1:10),sort(1:9,decreasing=TRUE),(2:12),sort(6:11,decreasing=TRUE),(7:13))
b1<- b
c1=c(
NA,NA,NA,NA,NA,NA,1,1,1,1,1,1,1,NA,NA,NA,NA,NA,NA,NA,NA,NA,NA,NA,2,2,2,2,2,2,2,2,2,2,2,NA,3,3,3,3,3,3,3)
?
?rl1<- rle(b1>=7)
?indx1<-(cumsum(rl1$lengths)+1)[!rl1$values]
?indx2<-(cumsum(rl1$lengths))[rl1$values]
b1[!b1>=7] <- NA
?lst1<-
split(sort(c(indx1,indx2)),((seq_along(sort(c(indx1,indx2)))-1)%/%2)+1)
mat1<- sapply(seq_along(lst1),function(i) {x<- lst1[[i]];?
b1[seq(x[1],x[2])]<- i; b1? })
indx2New<- !is.na(mat1[,2]) & mat1[,2]==2
?indx3New<- !is.na(mat1[,3]) & mat1[,3]==3
?mat1[!is.na(mat1[,1]) & mat1[,1]>3,1] <-
c(mat1[,2][indx2New],mat1[,3][indx3New])
?all.equal(c1,mat1[,1])
#[1] TRUE
A.K.
----- Original Message -----
From: Benjamin Gillespie <gybrg at leeds.ac.uk>
To: "r-help at R-project.org" <r-help at r-project.org>
Cc:
Sent: Wednesday, October 9, 2013 6:39 PM
Subject: [R] Possible loop/ if statement query
Dear r genii,
I hope you can help.
I have vector 'b':
b=c((1:10),sort(1:9,decreasing=TRUE),(2:12),sort(6:11,decreasing=TRUE),(7:13))
and, from 'b' I wish to create vector 'c':
c=c(???
NA,NA,NA,NA,NA,NA,1,1,1,1,1,1,1,NA,NA,NA,NA,NA,NA,NA,NA,NA,NA,NA,2,2,2,2,2,2,2,2,2,2,2,NA,3,3,3,3,3,3,3)
The rules I want to use to create 'c' are:
A numeric of equal to, or over 7 in 'b' needs to result in a numeric
(i.e. not NA) in 'c';
A numeric of less than 7 in 'b' needs to result in "NA" in
'c';
Where 'groups' of numerics equal to, or over 7 in 'b' are
present (i.e. next to each other in the list), the numerics produced in
'c' all need to be the same;
Each 'group' of numerics in 'b' must result in a unique numeric?
in 'c' (and, ideally, they should run in sequence as in 'c'
above (1,2,3...).
If anyone has any idea where to start on this or can crack it I'll be most
grateful!!
Many thanks in advance,
Ben Gillespie, Research Postgraduate
o-------------------------------------------------------------------o
School of Geography, University of Leeds, Leeds, LS2 9JT
o-------------------------------------------------------------------o
Tel: +44(0)113 34 33345
Mob: +44(0)770 868 7641
o-------------------------------o
http://www.geog.leeds.ac.uk/
o-------------------------------------o
@RiversBenG
o--------------o
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Hi not sure if it is the most efficient and clever solution ifelse(b<7, NA, cumsum(c(0,diff(!(b<7)))==1)) Regards Petr> -----Original Message----- > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r- > project.org] On Behalf Of Benjamin Gillespie > Sent: Thursday, October 10, 2013 12:39 AM > To: r-help at R-project.org > Subject: [R] Possible loop/ if statement query > > Dear r genii, > > I hope you can help. > > I have vector 'b': > > b=c((1:10),sort(1:9,decreasing=TRUE),(2:12),sort(6:11,decreasing=TRUE), > (7:13)) > > and, from 'b' I wish to create vector 'c': > > c=c( > NA,NA,NA,NA,NA,NA,1,1,1,1,1,1,1,NA,NA,NA,NA,NA,NA,NA,NA,NA,NA,NA, > 2,2,2,2,2,2,2,2,2,2,2,NA,3,3,3,3,3,3,3) > > The rules I want to use to create 'c' are: > > A numeric of equal to, or over 7 in 'b' needs to result in a numeric > (i.e. not NA) in 'c'; A numeric of less than 7 in 'b' needs to result > in "NA" in 'c'; Where 'groups' of numerics equal to, or over 7 in 'b' > are present (i.e. next to each other in the list), the numerics > produced in 'c' all need to be the same; Each 'group' of numerics in > 'b' must result in a unique numeric in 'c' (and, ideally, they should > run in sequence as in 'c' above (1,2,3...). > > If anyone has any idea where to start on this or can crack it I'll be > most grateful!! > > Many thanks in advance, > > Ben Gillespie, Research Postgraduate > o-------------------------------------------------------------------o > School of Geography, University of Leeds, Leeds, LS2 9JT o------------- > ------------------------------------------------------o > Tel: +44(0)113 34 33345 > Mob: +44(0)770 868 7641 > o-------------------------------o > http://www.geog.leeds.ac.uk/ > o-------------------------------------o > @RiversBenG > o--------------o > ______________________________________________ > 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.