[R] R2.11.1 seq.int difference between by and length.out

[R. Michael Weylandt]

What difference is it you are worried about:?

identical(seq.int(0,1,length.out = 11), seq.int(0,1, by = 0.1)) # TRUE

Though that may be OS dependent.

M

On Tue, Apr 10, 2012 at 10:51 AM, Alexander <juschitz_alexander at yahoo.de> wrote:
>
> Berend Hasselman wrote
>>
>> On 10-04-2012, at 15:54, Alexander wrote:
>>
>>> I am working under R2.11.1 Windows and I was wondering why there is a
>>> difference between
>>>
>>> seq.int(0,1,by=0.1)[4]-0.3
>>> seq.int(0,1,length.out=11)[4]-0.3
>>>
>>> there is also the fact that
>>>
>>> seq(0,1,by=0.1)[4]-0.3
>>> seq(0,1,length.out=11)[4]-0.3
>>>
>>> but I think this can be explained by floating precision...
>>
>>
>> R FAQ:  http://cran.r-project.org/doc/FAQ/R-FAQ.html
>>
>> 7.31 Why doesn't R think these numbers are equal?
>>
> This explains what the difference, but the problem for
>
> seq(2)*seq(2)==2
>
> is not the same as
>
> 0.3+0.1-0.4==0
>
> There must be a difference in the calculation for by and length.out in
> seq.int otherwise there wouldn't be a difference in seq.int
>
> seq.int(0,1,length.out=11)[4]-seq.int(0,1,by=0.1)[4]
>
> I am more interested in the generation of the sequence...
>
>
> Berend Hasselman wrote
>>
>> Berend
>>
>>
>>
>>
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>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>
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