Services & Resources / Wolfram Forums
MathGroup Archive
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 1998

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Re: warning for Round[Log[2]/Log[4]]

  • To: mathgroup at
  • Subject: [mg13955] Re: [mg13940] Re: warning for Round[Log[2]/Log[4]]
  • From: BobHanlon at
  • Date: Fri, 11 Sep 1998 15:06:45 -0400
  • Sender: owner-wri-mathgroup at

As you indicated, the problem occurs because numerical values are used
in attempting to evaluate the ratio. However,

Log[2]/Log[4] // Simplify







Bob Hanlon

In a message dated 9/8/98 5:06:18 AM, bruck at wrote:

>In article <6ssvo6$m9r at>,
>Wouter Meeussen  <eu000949 at> wrote:
>>** this is not a bug report ***
>>  Windows  
>[That Mathematica didn't have enough precision to compute
>Hmmm.  Interesting.  Since Log[2]/Log[4] = 1/2, Mathematica can't decide
>whether to round up or down--it SHOULD apply round-to-even, to give
>zero, but it's trying to do this with just numerical values.
>As I recall, deciding when A == B is a profoundly difficult problem. 
>I'm not sure how else one could go about this.  (Oh, sure, the
>immediate problem could be fixed by applying a special rule for
>logarithms, but what about special functions for which the relations
>are still undiscovered?)

  • Prev by Date: functions as arguments to functions.
  • Next by Date: Subscribe to MathGroup
  • Previous by thread: Re: warning for Round[Log[2]/Log[4]]
  • Next by thread: Re: Re: warning for Round[Log[2]/Log[4]]