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

Re: PolarPlot

• To: mathgroup at smc.vnet.net
• Subject: [mg87828] Re: PolarPlot
• From: Helen Read <read at math.uvm.edu>
• Date: Fri, 18 Apr 2008 02:39:29 -0400 (EDT)
• References: <ftmu5p$50d$1@smc.vnet.net> <ftv938$80f$1@smc.vnet.net> <fu1u66$oom$1@smc.vnet.net> <fu6me8$nml$1@smc.vnet.net>

dh wrote:
> 
> 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.
> 

I am not proposing anything. If you consult any calculus textbook, you 
will see that defining r as a directed distance (which may be negative) 
is *standard*.

And as for non-unique coordinates, this would be the case for polar 
coordinates even if we only allowed non-negative r, since you can always 
add or subtract any multiple of 2Pi from the angle.

--
Helen Read
University of Vermont