Re: Re: Re: Lower Floor
- To: mathgroup at smc.vnet.net
- Subject: [mg39135] Re: [mg39097] Re: [mg39040] Re: [mg39004] Lower Floor
- From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
- Date: Thu, 30 Jan 2003 01:08:26 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
It seems to be just the question of the way you input them. If instead of typing typing 20 zeros you simply enter 3.`20 everything works fine: Floor[3.`20] 3 It also saves you some effort! Andrzej Kozlowski Yokohama, Japan http://www.mimuw.edu.pl/~akoz/ http://platon.c.u-tokyo.ac.jp/andrzej/ On Wednesday, January 29, 2003, at 05:37 PM, Selwyn Hollis wrote: > 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 > To: mathgroup at smc.vnet.net >>> Sent: Saturday, January 25, 2003 7:27 AM >>> To: mathgroup at smc.vnet.net >>> Subject: [mg39135] [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! >>>> >>>> >>> >>> >> > > > >