[R] Bug or inaccuracy in cumsum( )

[Mai Zhou]

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