[R] seq

[Berton Gunter]

> Note however the result of
> 
>   0.1*(5:0) == 0.3)
>   [1] FALSE FALSE FALSE FALSE FALSE FALSE
> 
> as opposed to "==0.5", "==0.4", "==0.2", "==0.1" or "==0"!
> 
> I hope this helps,
> Ted.
> 
> 
> --------------------------------------------------------------------
> E-Mail: (Ted Harding) <Ted.Harding at nessie.mcc.ac.uk>
> Fax-to-email: +44 (0)870 167 1972
> Date: 03-Sep-04                                       Time: 13:59:59


At the risk of flailing at a dead and even dessicated horse ...

>From the Help file of identical(), the construction
identical(all.equal(x,y),TRUE) gives the desired test for equality for
finite precision arithmetic. Hence:

 > sapply(.1*(0:5),function(x)identical(all.equal(x,.3),TRUE))

[1] FALSE FALSE FALSE  TRUE FALSE FALSE

which is, presumably, as desired.

Cheers,

-- Bert Gunter
Genentech Non-Clinical Statistics
South San Francisco, CA
 
"The business of the statistician is to catalyze the scientific learning
process."  - George E. P. Box