[R] Variance for Vector of Constants is STILL Not Zero

[P Ehlers]

Barry,
Try the latest _patched_ version. I'm on 2006-02-12, but that may
already be superseded. I get var(x) = 0.

Peter Ehlers

Barry Zajdlik wrote:
> Hello all,
> 
> Thanks for the responses but I am still annoyed by this seemingly simple
> problem; I recorded sessionInfo() as below.
> 
> x<-rep(0.02,10)
> 
>>var(x)
> 
> [1] 1.337451e-35
> 
>> sessionInfo()
> 
> R version 2.1.0, 2005-04-18, i386-pc-mingw32 
> 
> attached base packages:
> [1] "methods"   "stats"     "graphics"  "grDevices" "utils"
> "datasets" 
> [7] "base"     
> 
> 
> 
> I then decided to download the latest version today but obtained the
> same result.
> 
> 
>>x<-rep(0.02,10)
>>var(x)
> 
> [1] 1.337451e-35
> 
> 
>>sessionInfo()
> 
> R version 2.2.1, 2005-12-20, i386-pc-mingw32 
> 
> attached base packages:
> [1] "methods"   "stats"     "graphics"  "grDevices" "utils"
> "datasets" 
> [7] "base"    
> 
> 
> I Changed .Machine$double.eps to make the calculations LESS accurate.
> My thought was that if I reduced the precision, 1-eps would return 1
> instead of some number less than 1.  My thought was that if eps were
> sufficiently large my sample problem would return a zero.  This didn't
> happen though.
> 
> Again, any thoughts would be appreciated.
> 
> Regards,
> Barry Zajdlik
> 
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