[Rd] x=.94 (PR#10529)

Peter Dalgaard p.dalgaard at biostat.ku.dk
Thu Dec 27 15:11:06 CET 2007


jrecta at gmail.com wrote:
> I am using R Version 2.6.2007-11-23.  I do not know if the problem exists
> for other values or versions
>
> I encountered a problem when searching for the number 0.94 and 0.95 in a
> vector of values.  I illustrate it below by creating a sequence of values 2
> ways and then looking for the value 0.94 (same result for 0.95).  It looks
> like the vector generated by seq( ) is a bit off:
>
>   
>> a<-seq(.9,.95,by=.01)
>> a
>>     
> [1] 0.90 0.91 0.92 0.93 0.94 0.95
>
>   
>> b<-c(.90,.91,.92,.93,.94,.95)
>> b
>>     
> [1] 0.90 0.91 0.92 0.93 0.94 0.95
>
>   
>> a==.94
>>     
> [1] FALSE FALSE FALSE FALSE FALSE FALSE
>   
>> b==.94
>>     
> [1] FALSE FALSE FALSE FALSE  TRUE FALSE
>
>   
>> a-b
>>     
> [1] 0.000000e+00 0.000000e+00 0.000000e+00 0.000000e+00 1.110223e-16
> [6] 1.110223e-16
>
> 	[[alternative HTML version deleted]]
>
>   
*Sigh*

FAQ 7.31

-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark          Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: (+45) 35327907



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