---------- Forwarded message ---------- From: Daniel Wheeler <[email protected]> Date: Wed, Jun 13, 2012 at 11:31 AM Subject: Fwd: Re: FiPy query To: Daniel Wheeler <[email protected]>
-------- Original Message -------- Subject: Re: FiPy query Date: Wed, 13 Jun 2012 10:52:04 -0400 From: Allawala, Altan <[email protected]> To: Wheeler, Daniel <[email protected]> Hello Daniel, Many thanks for your quick and helpful reply. I have reposted the question to the mailing list. In the mean time, I will have a look at the code that you created. The equation that I am trying to solve for is: 0=\frac{\partial\phi}{\partial x}+i*\frac{\partial^{2}\phi}{\partial x^{2}}-\frac{\partial^{3}\phi}{\partial x^{3}}+x^{2}\phi, where phi is complex. A rookie question, but what does it mean to be on /trunk? For the second question, I was thinking to do that as well - ie just split up the equations into real and imaginary parts and then solve them separately. But before starting, I wanted to just confirm that there's no other way to go about it. I'm using version 2.1.3 of FiPy on version 2.6 of Python. Thanks again for your help. Best, Altan On Wed, Jun 13, 2012 at 10:20 AM, Daniel Wheeler <[email protected] <mailto:[email protected]>> wrote: On 06/12/2012 03:12 PM, Allawala, Altan wrote: Hello Daniel, My apologies for contacting you on your email address but when I tried creating a FiPy ticket on matforge.org <http://matforge.org> <http://matforge.org> it wouldn't let me submit it as Trac deemed my question to be spam. No problem. You can always email the mailing list as well. <http://www.ctcms.nist.gov/__fipy/documentation/MAIL.html <http://www.ctcms.nist.gov/fipy/documentation/MAIL.html>> Repost this question to the list and I'll repost my answer as this is an interesting topic. 1) How does one solve for a triple derivative? The convection term can be used for a first order derivative and the diffusion term can be used for a second order (or any even ordered) derivative. But I can't find a single example where a PDE involving a third order derivative is solved. Combining a convection within a diffusion term (or vice-versa) isn't working. I have never actually tried this, but wondered myself. Am I right in saying that the term would be hyperbolic in nature? I coded something up on the fipy blog. <http://matforge.org/fipy/__blog/ThirdOrderTerm <http://matforge.org/fipy/blog/ThirdOrderTerm>> You need to be on trunk/ to couple equations like this. What version have you been using? 2) Secondly, can FiPy solve a PDE with complex coefficients? When I set a coefficient to an imaginary value (using j), it seems to simply ignore the entire term, suggesting that it only takes the real part of the PDE and then solves it. No. We haven't ever dealt with this. It probably isn't that hard to make it work. Can you split the equation into real and imaginary and solve them separately? -- Daniel Wheeler -- Daniel Wheeler _______________________________________________ fipy mailing list [email protected] http://www.ctcms.nist.gov/fipy [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]
