[R] Replacing NAs in long format

William Dunlap wdunlap at tibco.com
Sun Nov 4 01:37:37 CET 2012


ave() or split<-() can make that easier to write, although it
may take some time to internalize the idiom.  E.g.,

  > flag <- rep(NA, nrow(dat2)) # add as.integer if you prefer 1,0 over TRUE,FALSE
  > split(flag, dat2$idr) <- lapply(split(dat2, dat2$idr), function(d)with(d, any(schyear<=5 & year==0))) 
  > data.frame(dat2, flag)
    idr schyear year  flag
  1   1       4   -1  TRUE
  2   1       5    0  TRUE
  3   1       6    1  TRUE
  4   1       7    2  TRUE
  5   2       9    0 FALSE
  6   2      10    1 FALSE
  7   2      11    2 FALSE
or
  > ave(seq_len(nrow(dat2)), dat2$idr, FUN=function(i)with(dat2[i,], any(schyear<=5 & year==0))) 
  [1] 1 1 1 1 0 0 0
  > flag <- ave(seq_len(nrow(dat2)), dat2$idr, FUN=function(i)with(dat2[i,], any(schyear<=5 & year==0))) 
  > data.frame(dat2, flag)
    idr schyear year flag
  1   1       4   -1    1
  2   1       5    0    1
  3   1       6    1    1
  4   1       7    2    1
  5   2       9    0    0
  6   2      10    1    0
  7   2      11    2    0

Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf
> Of arun
> Sent: Saturday, November 03, 2012 5:01 PM
> To: Christopher Desjardins
> Cc: R help
> Subject: Re: [R] Replacing NAs in long format
> 
> Hi,
> May be this helps:
> dat2<-read.table(text="
> idr  schyear  year
> 1        4          -1
> 1        5            0
> 1        6            1
> 1        7            2
> 2        9            0
> 2        10            1
> 2        11          2
> ",sep="",header=TRUE)
> 
>  dat2$flag<-unlist(lapply(split(dat2,dat2$idr),function(x)
> rep(ifelse(any(apply(x,1,function(x) x[2]<=5 & x[3]==0)),1,0),nrow(x))),use.names=FALSE)
>  dat2
> #  idr schyear year flag
> #1   1       4   -1    1
> #2   1       5    0    1
> #3   1       6    1    1
> #4   1       7    2    1
> #5   2       9    0    0
> #6   2      10    1    0
> #7   2      11    2    0
> A.K.
> 
> 
> 
> 
> ----- Original Message -----
> From: Christopher Desjardins <cddesjardins at gmail.com>
> To: jim holtman <jholtman at gmail.com>
> Cc: r-help at r-project.org
> Sent: Saturday, November 3, 2012 7:09 PM
> Subject: Re: [R] Replacing NAs in long format
> 
> I have a similar sort of follow up and I bet I could reuse some of this
> code but I'm not sure how.
> 
> Let's say I want to create a flag that will be equal to 1 if schyear  < = 5
> and year = 0 for a given idr. For example
> 
> > dat
> 
> idr   schyear   year
> 1         4           -1
> 1         5            0
> 1         6            1
> 1         7            2
> 2         9            0
> 2        10            1
> 2        11           2
> 
> How could I make the data look like this?
> 
> idr   schyear   year   flag
> 1         4           -1     1
> 1         5            0     1
> 1         6            1     1
> 1         7            2     1
> 2         9            0     0
> 2        10            1    0
> 2        11           2     0
> 
> 
> I am not sure how to end up not getting both 0s and 1s for the 'flag'
> variable for an idr. For example,
> 
> dat$flag = ifelse(schyear <= 5 & year ==0, 1, 0)
> 
> Does not work because it will create:
> 
> idr   schyear   year   flag
> 1         4           -1     0
> 1         5            0     1
> 1         6            1     0
> 1         7            2     0
> 2         9            0     0
> 2        10            1    0
> 2        11           2     0
> 
> And thus flag changes for an idr. Which it shouldn't.
> 
> Thanks,
> Chris
> 
> 
> On Sat, Nov 3, 2012 at 5:50 PM, Christopher Desjardins <
> cddesjardins at gmail.com> wrote:
> 
> > Hi Jim,
> > Thank you so much. That does exactly what I want.
> > Chris
> >
> >
> > On Sat, Nov 3, 2012 at 1:30 PM, jim holtman <jholtman at gmail.com> wrote:
> >
> >> > x <- read.table(text = "idr  schyear year
> >> +  1       8    0
> >> +  1       9    1
> >> +  1      10   NA
> >> +  2       4   NA
> >> +  2       5   -1
> >> +  2       6    0
> >> +  2       7    1
> >> +  2       8    2
> >> +  2       9    3
> >> +  2      10    4
> >> +  2      11   NA
> >> +  2      12    6
> >> +  3       4   NA
> >> +  3       5   -2
> >> +  3       6   -1
> >> +  3       7    0
> >> +  3       8    1
> >> +  3       9    2
> >> +  3      10    3
> >> +  3      11   NA", header = TRUE)
> >> >  # you did not specify if there might be multiple contiguous NAs,
> >> >  # so there are a lot of checks to be made
> >> >  x.l <- lapply(split(x, x$idr), function(.idr){
> >> +     # check for all NAs -- just return indeterminate state
> >> +     if (sum(is.na(.idr$year)) == nrow(.idr)) return(.idr)
> >> +     # repeat until all NAs have been fixed; takes care of contiguous
> >> ones
> >> +     while (any(is.na(.idr$year))){
> >> +         # find all the NAs
> >> +         for (i in which(is.na(.idr$year))){
> >> +             if ((i == 1L) && (!is.na(.idr$year[i + 1L]))){
> >> +                 .idr$year[i] <- .idr$year[i + 1L] - 1
> >> +             } else if ((i > 1L) && (!is.na(.idr$year[i - 1L]))){
> >> +                 .idr$year[i] <- .idr$year[i - 1L] + 1
> >> +             } else if ((i < nrow(.idr)) && (!is.na(.idr$year[i +
> >> 1L]))){
> >> +                 .idr$year[i] <- .idr$year[i + 1L] -1
> >> +             }
> >> +         }
> >> +     }
> >> +     return(.idr)
> >> + })
> >> > do.call(rbind, x.l)
> >>      idr schyear year
> >> 1.1    1       8    0
> >> 1.2    1       9    1
> >> 1.3    1      10    2
> >> 2.4    2       4   -2
> >> 2.5    2       5   -1
> >> 2.6    2       6    0
> >> 2.7    2       7    1
> >> 2.8    2       8    2
> >> 2.9    2       9    3
> >> 2.10   2      10    4
> >> 2.11   2      11    5
> >> 2.12   2      12    6
> >> 3.13   3       4   -3
> >> 3.14   3       5   -2
> >> 3.15   3       6   -1
> >> 3.16   3       7    0
> >> 3.17   3       8    1
> >> 3.18   3       9    2
> >> 3.19   3      10    3
> >> 3.20   3      11    4
> >> >
> >> >
> >>
> >>
> >> On Sat, Nov 3, 2012 at 1:14 PM, Christopher Desjardins
> >> <cddesjardins at gmail.com> wrote:
> >> > Hi,
> >> > I have the following data:
> >> >
> >> >> data[1:20,c(1,2,20)]
> >> > idr  schyear year
> >> > 1       8    0
> >> > 1       9    1
> >> > 1      10   NA
> >> > 2       4   NA
> >> > 2       5   -1
> >> > 2       6    0
> >> > 2       7    1
> >> > 2       8    2
> >> > 2       9    3
> >> > 2      10    4
> >> > 2      11   NA
> >> > 2      12    6
> >> > 3       4   NA
> >> > 3       5   -2
> >> > 3       6   -1
> >> > 3       7    0
> >> > 3       8    1
> >> > 3       9    2
> >> > 3      10    3
> >> > 3      11   NA
> >> >
> >> > What I want to do is replace the NAs in the year variable with the
> >> > following:
> >> >
> >> > idr  schyear year
> >> > 1       8    0
> >> > 1       9    1
> >> > 1      10   2
> >> > 2       4   -2
> >> > 2       5   -1
> >> > 2       6    0
> >> > 2       7    1
> >> > 2       8    2
> >> > 2       9    3
> >> > 2      10    4
> >> > 2      11   5
> >> > 2      12    6
> >> > 3       4   -3
> >> > 3       5   -2
> >> > 3       6   -1
> >> > 3       7    0
> >> > 3       8    1
> >> > 3       9    2
> >> > 3      10    3
> >> > 3      11   4
> >> >
> >> > I have no idea how to do this. What it needs to do is make sure that for
> >> > each subject (idr) that it either adds a 1 if it is preceded by a value
> >> in
> >> > year or subtracts a 1 if it comes before a year value.
> >> >
> >> > Does that make sense? I could do this in Excel but I am at a loss for
> >> how
> >> > to do this in R. Please reply to me as well as the list if you respond.
> >> >
> >> > Thanks!
> >> > Chris
> >> >
> >> >         [[alternative HTML version deleted]]
> >> >
> >> > ______________________________________________
> >> > 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.
> >>
> >>
> >>
> >> --
> >> Jim Holtman
> >> Data Munger Guru
> >>
> >> What is the problem that you are trying to solve?
> >> Tell me what you want to do, not how you want to do it.
> >>
> >
> >
> 
>     [[alternative HTML version deleted]]
> 
> ______________________________________________
> 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.
> 
> 
> ______________________________________________
> 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.




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