Re: replicating variables
- To: mathgroup at smc.vnet.net
- Subject: [mg43693] Re: [mg43683] replicating variables
- From: sean kim <sean_incali at yahoo.com>
- Date: Tue, 30 Sep 2003 16:42:42 -0400 (EDT)
- Reply-to: sean_incali01 at yahoo.com
- Sender: owner-wri-mathgroup at wolfram.com
this might be little more visible. let's use a different initial conditions. now you see something happening. i'll let yoiu decide if the initial conditions are reasonable. In[1]:= nlde = {a'[t] == a[t] (3 - 2 b[t] - a[t]), b'[t] == b[t] (2 - a[t] - b[t])} nldeics = Join[nlde, {a[0] == 0.001, b[0] == 1}] sol = NDSolve[ nldeics, {a, b}, {t, 0, 1}] Flatten[Evaluate[{a[t], b[t]} /. sol]] Plot[a[t]/.sol, {t, 0,1}] Plot[b[t]/.sol, {t, 0,1}] ParametricPlot[Evaluate[{a[t], b[t]} /. sol], {t, 0, 1}]; --- Young Kim <kim17 at fas.harvard.edu> wrote: > Hi, > > Let's say I have two non linear differential > equations which cannot be > analytically solved, > for example, > > a[t]' == a[t] { 3 - 2 b[t] - a[t] } > b[t]' == b[t] { 2 - a[t] - b[t] } > > What do I need to do if I want to draw parametric > curve of > r[t] = { a[t], b[t] }, or { a[t], b[t], t } in 3D > where a[t] , b[t] > are the numerical solutions of the preceding > equations. > Thanks. > > Young > > > ===== My email acct's are filling up too fast due to the mass emailed virus attchments. I have remedied this by including a reply to address. I won't receive any replies sent to sean_incali at yahoo.com, instead they will get bounced to the sender. Reply to sean_incali01@yahooDOTcom. __________________________________ Do you Yahoo!? The New Yahoo! Shopping - with improved product search http://shopping.yahoo.com