Re: Very strange behaviour of ArcTan[]
- To: mathgroup at smc.vnet.net
- Subject: [mg102681] Re: [mg102656] Very strange behaviour of ArcTan[]
- From: "Tony Harker" <a.harker at ucl.ac.uk>
- Date: Tue, 18 Aug 2009 06:10:27 -0400 (EDT)
- References: <200908171206.IAA06945@smc.vnet.net>
Dear Alexey, Why are you surprised by the output? ArcTan is doing exactly what it should when called with two arguments: In[1]:= ArcTan[.5, $MachinePrecision] ArcTan[.5] $MachinePrecision $MachinePrecision/.5 ArcTan[%] Out[1]= 1.53947 Out[2]= 0.463648 Out[3]= 15.9546 Out[4]= 31.9092 Out[5]= 1.53947 Tony Harker ]-> -----Original Message----- ]-> From: Alexey [mailto:lehin.p at gmail.com] ]-> Sent: 17 August 2009 13:07 ]-> To: mathgroup at smc.vnet.net ]-> Subject: [mg102656] Very strange behaviour of ArcTan[] ]-> ]-> Hello, ]-> I just have discovered some strange (buggy?) feature of ]-> ArcTan[] function in Mathematica 5.2. Try the following; ]-> ]-> In[72]:= ]-> ArcTan[.5,$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[]