Re: drawing tilted ellipses?

*To*: mathgroup at smc.vnet.net*Subject*: [mg20493] Re: drawing tilted ellipses?*From*: adam.smith at hillsdale.edu*Date*: Wed, 27 Oct 1999 02:04:55 -0400*References*: <7v3bmr$5te@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

This is easily possible. First parameterize your ellipse. Then use a rotation matrix to transform the {x,y} coordinates into a tilted set. Below is my code (Maybe not the most elegant, but it works). I used "Evaluate" inside the plot to avoid an annoying but harmless warning message. Also, be sure to set AspectRatio->Automatic or Mathematica will scale the height/width in such a way that your ellipse won't have the proper "look". In[1]:= ellipse = {3 *Cos[2*Pi*t],2*Sin[2*Pi*t]}; In[2]:= ParametricPlot[ Evaluate[ellipse],{t,0,1},AspectRatio->Automatic]; In[3]:= theta = 30*Pi/180; rotmatrix = {{Cos[theta],-Sin[theta]},{Sin[theta],Cos[theta]}}; tiltedellipse = rotmatrix.ellipse Clear[theta]; In[4]:= ParametricPlot[ Evaluate[tiltedellipse],{t,0,1},AspectRatio->Automatic]; Adam Smith In article <7v3bmr$5te at smc.vnet.net>, Joe Strout <joe at strout.net> wrote: > Is it possible to draw an ellipse in Mathematica that is not orthogonal > to the XY axes? E.g., leaning over 30 degrees? > > I thought perhaps I could specify it orthogonally and then apply a > rotation transformation, but the only transformations available seem to > be scaling (Scaled) and translation (Offset). > > Of course I could use a series of line segments, but I want this to be > smooth even when printed on a high-resolution printer. Any tips? > > Thanks, > -- Joe > > -- > ,------------------------------------------------------------------. > | Joseph J. Strout Biocomputing -- The Salk Institute | > | joe at strout.net http://www.strout.net | > `------------------------------------------------------------------' > Check out the Mac Web Directory! http://www.strout.net/macweb.cgi > > Sent via Deja.com http://www.deja.com/ Before you buy.