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

MathGroup Archive 2008

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

Search the Archive

Re: PolarPlot

  • To: mathgroup at smc.vnet.net
  • Subject: [mg87775] Re: PolarPlot
  • From: dh <dh at metrohm.ch>
  • Date: Wed, 16 Apr 2008 22:31:45 -0400 (EDT)
  • References: <ftmu5p$50d$1@smc.vnet.net> <ftv938$80f$1@smc.vnet.net> <fu1u66$oom$1@smc.vnet.net>


Hi Helen,

just saw your reply. A coordinate system as you propose would assign 

more than one coordinate tuple to any point. Although I can see 

aplications in graphics (cycloids...), I do not think that this makes 

life easier for calculations. There are enough problems with unique 

maps, no need to make artificial ones.

Daniel



Helen Read wrote:

> dh wrote:

>> Hi Bruce,

>>

>> the radius in polar coordinates has to be real and positive. Therefore, 

> 

> Actually, no. In polar coordinates r is a *directed* distance, which may 

> be positive or negative.

> 

>> r=Sqrt[Cos[phi]] can not be the correct formula, we would get imaginary 

>>

>> values. To prevent this, we may e.g. write: r=Sqrt[Abs[Cos[phi]] what 

>>

>> gives the plot you are looking for.

>>

>> hope this helps, Daniel

> 




  • Prev by Date: Re: List re-arrangement question
  • Next by Date: heat equation through different media/problem with constant flux at
  • Previous by thread: Re: PolarPlot
  • Next by thread: Re: PolarPlot