Re: Plotting iso-distance curves from matrices

*To*: mathgroup at smc.vnet.net*Subject*: [mg71003] Re: [mg70958] Plotting iso-distance curves from matrices*From*: Carl Woll <carlw at wolfram.com>*Date*: Sat, 4 Nov 2006 04:08:16 -0500 (EST)*References*: <200611030639.BAA20920@smc.vnet.net>

Uwe Ziegenhagen wrote: >Hi, > >I would like to plot iso-distance curves (in 2 dimensions) satisfying >the following condition: > >{ x \in R^2 | (x-x_0)^T A (x-x_0) = d^2} > >with x a 2x1 vector, ^T denoting the transposed sign and A a positive >definite matrix. Any way to do it in Mathematica? > >Uwe > > Use ContourPlot. For example: a = Table[ Random[], {2}, {2}]; ContourPlot[{x-2,y-1}.a.{x-2,y-1}, {x,-5,5}, {y,-5,5}] Carl Woll Wolfram Research

**References**:**Plotting iso-distance curves from matrices***From:*Uwe Ziegenhagen <newsgroup@ziegenhagen.info>