[R] Odd behaviour of R 2.00
Hiroto Miyoshi
h_m_ at po.harenet.ne.jp
Sun Nov 14 13:48:35 CET 2004
Dear Professor Ripley and Professor Dalgaard
Thank you for your quick reply.
Now, I understand.
Thank you.
--------------------------------
Hiroto Miyoshi
h_m_ at po.harenet.ne.jp
----- Original Message -----
From: "Prof Brian Ripley" <ripley at stats.ox.ac.uk>
To: "Hiroto Miyoshi" <h_m_ at po.harenet.ne.jp>
Cc: "Peter Dalgaard" <p.dalgaard at biostat.ku.dk>; <r-help at stat.math.ethz.ch>
Sent: Sunday, November 14, 2004 9:27 PM
Subject: Re: [R] Odd behaviour of R 2.00
> On Sun, 14 Nov 2004, Hiroto Miyoshi wrote:
>
> > Dear Professor Dalgaard
> >
> >> It is the NA pattern on the left hand side that matters. Does it help
> >> to use
> >>
> >> seishin[!is.na(seishin) & seishin==""]<-NA
> >>
> >> ?
> >
> > Yes! the above line worked perfectly.
> > But why? To me, !is.na(seishin) & seishin=="" seems redundant.
> > If you could explain this, it would be greatly appreciated.
>
> Without it, your logical matrix index contains NA. What do you intend
> that to do? Do you replace the corresponding element or not? You don't
> know, so perhaps you set it to NA, whatever the rhs? And do you use up a
> value on the rhs or not (not relevant if as here you are recycling a
> single value, except that you need to know how many times to recycle it)?
>
> Prior to 2.0.0, R behaved inconsistently (both within itself and with S)
> with NA indices in assignments, so now we force the user to say what he
> intended. This has picked up quite a number of errors.
>
> I do think this would be cleaner and faster using a loop over columns,
> especially as you probably have factors in the data frame. Read the code
> of "[<-.data.frame" if you don't see that.
>
>
> > Thank you.
> > --------------------------------
> > Hiroto Miyoshi
> > h_m_ at po.harenet.ne.jp
--------------------------------
Hiroto Miyoshi
h_m_ at po.harenet.ne.jp
----- Original Message -----
From: "Peter Dalgaard" <p.dalgaard at biostat.ku.dk>
To: "Hiroto Miyoshi" <h_m_ at po.harenet.ne.jp>
Cc: "Peter Dalgaard" <p.dalgaard at biostat.ku.dk>;
<r-help at hypatia.math.ethz.ch>
Sent: Sunday, November 14, 2004 9:27 PM
Subject: Re: [R] Odd behaviour of R 2.00
> "Hiroto Miyoshi" <h_m_ at po.harenet.ne.jp> writes:
>
> > Dear Professor Dalgaard
> >
> > > It is the NA pattern on the left hand side that matters. Does it help
> > > to use
> > >
> > > seishin[!is.na(seishin) & seishin==""]<-NA
> > >
> > > ?
> >
> > Yes! the above line worked perfectly.
> > But why? To me, !is.na(seishin) & seishin=="" seems redundant.
> > If you could explain this, it would be greatly appreciated.
> > Thank you.
>
> It's due to this change (do check the NEWS file when things change
> unexpectedly...):
>
> o Subassignments involving NAs and with a replacement value of
> length > 1 are now disallowed. (They were handled
> inconsistently in R < 2.0.0, see PR#7210.) For data frames
> they are disallowed altogether, even for logical matrix indices
> (the only case which used to work).
>
> Now, I'm getting slightly confused here, since there appears to be
> exceptions:
>
> > str(c)
> `data.frame': 10 obs. of 2 variables:
> $ a: Factor w/ 10 levels "1","10","2","3",..: 1 3 4 5 6 NA 8 9 10 2
> $ b: Factor w/ 9 levels "","a","b","e",..: 2 3 1 NA 4 5 6 7 8 9
> > c[c==""]<-NA
> > str(c)
> `data.frame': 10 obs. of 2 variables:
> $ a: Factor w/ 10 levels "1","10","2","3",..: 1 3 4 5 6 NA 8 9 10 2
> $ b: Factor w/ 9 levels "","a","b","e",..: 2 3 NA NA 4 5 6 7 8 9
>
> > version
> _
> platform i686-pc-linux-gnu
> arch i686
> os linux-gnu
> system i686, linux-gnu
> status
> major 2
> minor 0.0
> year 2004
> month 10
> day 04
> language R
>
> Also:
>
> > aq <- airquality
> > aq[aq==5] <- 98765432
> > aq[aq==97] <- 98765432
> Error: NAs are not allowed in subscripted assignments
>
> (difference being that 97 occurs in columns with NA's and 5 does not)
>
> --
> O__ ---- Peter Dalgaard Blegdamsvej 3
> c/ /'_ --- Dept. of Biostatistics 2200 Cph. N
> (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918
> ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk) FAX: (+45) 35327907
>
>
> > ----- Original Message -----
> > From: "Peter Dalgaard" <p.dalgaard at biostat.ku.dk>
> > To: "Hiroto Miyoshi" <h_m_ at po.harenet.ne.jp>
> > Cc: <r-help at stat.math.ethz.ch>
> > Sent: Sunday, November 14, 2004 7:26 PM
> > Subject: Re: [R] Odd behaviour of R 2.00
> >
> >
> >> "Hiroto Miyoshi" <h_m_ at po.harenet.ne.jp> writes:
> >>
> >>> Dear R users
> >>>
> >>> I have a data frame containing character and numeric variables, whose
> >>> name is seishin. When I tried to assign NA to "" in the data frame,
R,
> > 2.00
> >>> showed an error message, such as
> >>>
> >>>> seishin[seishin==""]<-NA
> >>> Error: NAs are not allowed in subscripted assignments
> >>>
> >>> This did not happen under R 1.9.0.
> >>>
> >>> More oddly,
> >>> The following commands work just fine under R 2.0.0
> >>>> a<-1:10
> >>>> b<-letters[1:10]
> >>>> b[3]<-""
> >>>> c<-data.frame(cbind(a,b))
> >>>> c[c==""]<-NA
> >>>
> >>> Why is this so?
> >>
> >>
> >> (For atomic vectors you could also use %in% instead of ==, but this
> >> doesn't work with data frames.)
> >>
> >>> And how can I assign NA to "" data.framewise in seishin data.frame?
> >>
> >> --
> >> O__ ---- Peter Dalgaard Blegdamsvej 3
> >> c/ /'_ --- Dept. of Biostatistics 2200 Cph. N
> >> (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918
> >> ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk) FAX: (+45) 35327907
> >>
> >> ______________________________________________
> >> R-help at stat.math.ethz.ch mailing list
> >> https://stat.ethz.ch/mailman/listinfo/r-help
> >> PLEASE do read the posting guide!
> > http://www.R-project.org/posting-guide.html
> >>
> >>
> >
> > ______________________________________________
> > R-help at stat.math.ethz.ch mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
> >
> >
>
> --
> Brian D. Ripley, ripley at stats.ox.ac.uk
> Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
> University of Oxford, Tel: +44 1865 272861 (self)
> 1 South Parks Road, +44 1865 272866 (PA)
> Oxford OX1 3TG, UK Fax: +44 1865 272595
>
>
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