Mathematica 9 is now available
Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2009

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

Search the Archive

Re: Very strange behaviour of ArcTan[]

  • To: mathgroup at smc.vnet.net
  • Subject: [mg102682] Re: Very strange behaviour of ArcTan[]
  • From: Szabolcs Horvát <szhorvat at gmail.com>
  • Date: Tue, 18 Aug 2009 06:10:39 -0400 (EDT)
  • References: <h6bh4m$6ov$1@smc.vnet.net>

On 2009.08.17. 14:06, Alexey wrote:
> Hello,
> I just have discovered some strange (buggy?) feature of ArcTan[]
> function in Mathematica 5.2. Try the following;
>
> In[72]:=
> ArcTan[.5,$MachinePrecision]
> ArcTan[.5]
>
> Out[72]=
> 1.53947
>
> Out[73]=
> 0.463648
>
> The expression ArcTan[.5,$MachinePrecision] must (?) give an error but
> in really gives some strange output without any error messages... What
> do you think about this?

What are you trying to do?  According to the docs, "ArcTan[x,y] gives 
the arc tangent of y/x, taking into account which quadrant the point 
(x,y) is in."


  • Prev by Date: Re: Standard deviations and Confidence intervals with respect to
  • Next by Date: Re: Very strange behaviour of ArcTan[]
  • Previous by thread: Re: Very strange behaviour of ArcTan[]
  • Next by thread: Re: Very strange behaviour of ArcTan[]