[R] Bug or inaccuracy in cumsum( )

[Erik Iverson]

Third one this afternoon, see FAQ 7.31

Mai Zhou wrote:
> I came across this: shouldn't the last value be a more exact zero?
> It did not do that with  1 - sum( rep(0.1, 10) )
> 
> 
>>  1 - cumsum( rep(0.1, 10) )
>  [1] 9.000000e-01 8.000000e-01 7.000000e-01 6.000000e-01 5.000000e-01
>                                4.000000e-01 3.000000e-01 2.000000e-01
>  [9] 1.000000e-01 1.110223e-16
>> version
>                _                           
> platform       i386-pc-mingw32             
> arch           i386                        
> os             mingw32                     
> system         i386, mingw32               
> status                                     
> major          2                           
> minor          7.1                         
> year           2008                        
> month          06                          
> day            23                          
> svn rev        45970                       
> language       R                           
> version.string R version 2.7.1 (2008-06-23)
> 
> 
> 
> 
> best,
> 
> 
> Mai Z
> 
> ______________________________________________
> 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.