R devel - Mar 2003 - density(), with argument of length 1 (PR#2593)

The following is from version 1.6.2 of R under Windows,
or 1.6.1 under Mac OSX/X11
> density(1)
Error in if (!(lo <- min(hi, IQR(x)/1.34))) (lo <- hi) || (lo <-
abs(x[1])) ||  :
        missing value where logical needed

I am not sure how this should be handled.  I encountered it
in connection with densityplot().  In that connection, it
might be enough to modify density() so that it returns NA 
is these circumstances.  The following demonstrates the 
implications for densityplot().
> data(mtcars)
> attach(mtcars)
> x11()
> densityplot(~mpg | carb)
Error in if (!(lo <- min(hi, IQR(x)/1.34))) (lo <- hi) || (lo <-
abs(x[1])) ||  :
        missing value where logical needed

John Maindonald                     email : john.maindonald@anu.edu.au
Centre for Bioinformation Science,  phone : (6125)3473        
c/o MSI,                            fax   : (6125)5549 
John Dedman Mathematical Sciences Building (Building 27)
Australian National University
Canberra ACT 0200
Australia

u9801539@leonard.anu.edu.au writes:
> The following is from version 1.6.2 of R under Windows,
> or 1.6.1 under Mac OSX/X11
> 
> > density(1)
> Error in if (!(lo <- min(hi, IQR(x)/1.34))) (lo <- hi) || (lo <-
abs(x[1])) ||  :
>         missing value where logical needed
> 
> I am not sure how this should be handled.
It comes from this bit of code:
> bw.nrd0
function (x)
{
    hi <- sd(x)
    if (!(lo <- min(hi, IQR(x)/1.34)))
        (lo <- hi) || (lo <- abs(x[1])) || (lo <- 1)
    0.9 * lo * length(x)^(-0.2)
}

in which hi is NA if x has length 1. A pragmatic way out would seem to
be to change the first line to 

hi <- if (length(x) > 1) sd(x) else 0

(and I wonder why the author didn't go all the way with the ||
sneakiness and said

    (lo <- min(hi, IQR(x)/1.34)) ||
        (lo <- hi) || (lo <- abs(x[1])) || (lo <- 1)

)


-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard@biostat.ku.dk)             FAX: (+45) 35327907

> From p.dalgaard@biostat.ku.dk  Sat Mar  1 21:22:47 2003
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> To: u9801539@leonard.anu.edu.au
> Cc: r-devel@stat.math.ethz.ch, R-bugs@biostat.ku.dk
> Subject: Re: [Rd] density(), with argument of length 1 (PR#2593)
> From: Peter Dalgaard BSA <p.dalgaard@biostat.ku.dk>
> Date: 01 Mar 2003 11:22:48 +0100
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> u9801539@leonard.anu.edu.au writes:
> 
> > The following is from version 1.6.2 of R under Windows,
> > or 1.6.1 under Mac OSX/X11
> > 
> > > density(1)
> > Error in if (!(lo <- min(hi, IQR(x)/1.34))) (lo <- hi) || (lo
<- abs(x[1])) ||  :
> >         missing value where logical needed
> > 
> > I am not sure how this should be handled.
> 
> It comes from this bit of code:
> 
> > bw.nrd0
> function (x)
> {
>     hi <- sd(x)
>     if (!(lo <- min(hi, IQR(x)/1.34)))
>         (lo <- hi) || (lo <- abs(x[1])) || (lo <- 1)
>     0.9 * lo * length(x)^(-0.2)
> }
> 
> in which hi is NA if x has length 1. A pragmatic way out would seem to
> be to change the first line to 
> 
> hi <- if (length(x) > 1) sd(x) else 0
> 
> (and I wonder why the author didn't go all the way with the ||
> sneakiness and said
> 
>     (lo <- min(hi, IQR(x)/1.34)) ||
>         (lo <- hi) || (lo <- abs(x[1])) || (lo <- 1)
Note that two of the other three bandwith rules also require
attention:
> bw.ucv(1)
Error in fmin(function(arg) f(arg, ...), lower, upper, tol) : 
        invalid xmin value
> bw.SJ(1)
Error in TDh(cnt, b, n, d) : NA/NaN/Inf in foreign function call (arg 5)

The remaining rule has:
> bw.nrd(1)
[1] NA
which is reasonable.









John Maindonald                     email : john.maindonald@anu.edu.au
Centre for Bioinformation Science,  phone : (6125)3473        
c/o MSI,                            fax   : (6125)5549 
John Dedman Mathematical Sciences Building (Building 27)
Australian National University
Canberra ACT 0200
Australia