Re: Very strange behaviour of ArcTan[]
- To: mathgroup at smc.vnet.net
- Subject: [mg102667] Re: [mg102656] Very strange behaviour of ArcTan[]
- From: Adriano Pascoletti <adriano.pascoletti at dimi.uniud.it>
- Date: Tue, 18 Aug 2009 06:07:53 -0400 (EDT)
- References: <200908171206.IAA06945@smc.vnet.net>
Alexey, ArcTan[x,y] gives the arc tangent y/x taking into account which quadrant the point (x,y) is in In[1]:= $MachinePrecision Out[1]= 15.9546 In[4]:= ArcTan[0.5, $MachinePrecision] Out[4]= 1.5394676360951292 In[5]:= ArcTan[$MachinePrecision/0.5] Out[5]= 1.539467636095129 Adriano Pascoletti 2009/8/17 Alexey <lehin.p at gmail.com> > 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? > >
- References:
- Very strange behaviour of ArcTan[]
- From: Alexey <lehin.p@gmail.com>
- Very strange behaviour of ArcTan[]