Re: Re: Lower Floor
- To: mathgroup at smc.vnet.net
- Subject: [mg39097] Re: [mg39040] Re: [mg39004] Lower Floor
- From: Selwyn Hollis <selwynh at earthlink.net>
- Date: Wed, 29 Jan 2003 03:37:54 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
I realize that we're dealing with the vagaries of internal arithmetic,
but it is highly disquieting that 3.000... (with any number of zeros)
would ever be anything but the binary floating-point number .11 * 2^2 !
Selwyn
On Monday, January 27, 2003, at 02:55 AM, Wolf, Hartmut wrote:
> Selwyn,
>
> things aren't, what they appear to be:
>
> In[2]:= Through[{InputForm, Floor}[#]] & /@
> {3.0000000000000000, 3.00000000000000000}
> Out[2]= {{3., 3},
> {2.999999999999999999999999999991459`17.6021, 2}}
>
> You're right, of course, perhaps, except for wow.
>
> --
> Hartmut
>
>
>> -----Original Message-----
>> From: Selwyn Hollis [mailto:selwynh at earthlink.net]
To: mathgroup at smc.vnet.net
>> Sent: Saturday, January 25, 2003 7:27 AM
>> To: mathgroup at smc.vnet.net
>> Subject: [mg39097] [mg39040] Re: [mg39004] Lower Floor
>>
>>
>> Wow. But apparently it has nothing to do with Log. Look:
>>
>> Floor[3.0000000000000000]
>>
>> 3
>>
>> Floor[3.00000000000000000]
>>
>> 2
>>
>> ---
>> Selwyn Hollis
>>
>>
>>
>> On Friday, January 24, 2003, at 05:05 AM, André Giroux wrote:
>>
>>> Hi All.
>>> With Mathematica 4.1 on Windows98:
>>> N[Log[8]/Log[2]]
>>> 3.
>>> Floor[N[Log[8]/Log[2]]]
>>> 2
>>> Beware!
>>>
>>>
>>
>>
>