Re: Plot of Nonlinear function
- To: mathgroup at smc.vnet.net
- Subject: [mg40902] Re: Plot of Nonlinear function
- From: "Bill Bertram" <wkb at ansto.gov.au>
- Date: Wed, 23 Apr 2003 05:17:33 -0400 (EDT)
- Organization: Australian Nuclear Science and Technology Organisation
- References: <b8582c$5pj$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
"Jong Choi" <jxc91 at po.cwru.edu> wrote in message news:b8582c$5pj$1 at smc.vnet.net... > I want to plot this funcion with theta1 vs. theta2 > > > (theta1-pi/2) * Sin[theta1+theta2] - (theta2-pi/2) * (Sin[theta1] + > Sin[theta1+theta2]) = 0 > > this function is not linear. > the values of x axis are theta1 and those of y axis are theta2. > I think I have to solve this fuction first and then plot. > Just a follow-up from my previous posting. If you ContourPlot the Lefthand-side of your equation in the range {theta1,-Pi, Pi}, {theta2, -Pi, Pi} you'll see that the function has a saddle point near x = -0.5, y = 0.3. This makes the method I gave in my previous posting break down in this region. FindRoot doesn't work too well near saddle points.