MathGroup Archive 2013

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

Search the Archive

Re: Round-off error?


On 11/4/13 at 11:17 PM, fateman at cs.berkeley.edu (Richard Fateman)
wrote:

>On 11/1/2013 11:21 PM, Bill Rowe wrote:

>>shows the two machine precision numbers differ by 1 bit and
>>consequently are considered equal by Equal as documented.

>>This type of issue is inherent in floating point arithmetic done on
>>any modern computer.

>This is not at all true.  Mathematica chooses to implement a fuzzy
>version of equality that does not correspond to any hardware
>floating-point operation on any modern computer that I am aware of.

Just to clarify my comment. My intended meaning was (n+1)*dt
will differ from n*dt+dt for some values of n and dt, a
characteristic of any modern computer and a fundamental
characteristic of floating point arithmetic. I had not intended
to imply Mathematica's design for Equal is universal.




  • Prev by Date: Number Separator for Number Labels on Plot Axes
  • Next by Date: Re: ListPlot - assigning a list of colors to a set of points
  • Previous by thread: Re: Round-off error?
  • Next by thread: Solve PDE system with 3 variables