tag:blogger.com,1999:blog-5822805028291837738.post1571451645444189289..comments2020-06-01T01:53:36.438-04:00Comments on Various Consequences: Three Dimensional Poisson's EquationJoshua Stultshttp://www.blogger.com/profile/03506970399027046387noreply@blogger.comBlogger10125tag:blogger.com,1999:blog-5822805028291837738.post-49796410887879633922014-06-11T13:16:42.539-04:002014-06-11T13:16:42.539-04:00I want to write maxima code for solve difference e...I want to write maxima code for solve difference equation for PDE in heat equation in 1 dimentional <br />please send me e-mail:bhagya4us@gmail.comAnonymoushttps://www.blogger.com/profile/12560884307326608543noreply@blogger.comtag:blogger.com,1999:blog-5822805028291837738.post-25903106654290475342009-11-24T17:46:21.093-05:002009-11-24T17:46:21.093-05:00I think if you tell folks what you are trying to m...I think if you tell folks what you are trying to model with your PDE that might motivate more interest.Joshua Stultshttps://www.blogger.com/profile/03506970399027046387noreply@blogger.comtag:blogger.com,1999:blog-5822805028291837738.post-86492477956671833752009-11-24T13:40:24.333-05:002009-11-24T13:40:24.333-05:00O.K. Grate.
Really thanks for your interesting di...O.K. Grate.<br /><br />Really thanks for your interesting discussion. I just wait for a professional person in this Field. <br />PLEASE SEND ME E-MAIL 'Phymalidoust@gmail.com'Mohammadhttps://www.blogger.com/profile/12765617084693177981noreply@blogger.comtag:blogger.com,1999:blog-5822805028291837738.post-18412593829575370452009-11-24T13:18:48.383-05:002009-11-24T13:18:48.383-05:00Thank you, I appreciate your offer, but I don'...Thank you, I appreciate your offer, but I don't think this lines up with my current research interests. <br /><br />I think it is good to get these posts up though, perhaps one of the other readers will be interested (this is the most read post on my site, ~150 views/month), and they can contact you through your profile.Joshua Stultshttps://www.blogger.com/profile/03506970399027046387noreply@blogger.comtag:blogger.com,1999:blog-5822805028291837738.post-16393526516821099802009-11-24T13:12:40.576-05:002009-11-24T13:12:40.576-05:00It is simply a collaboration if you are willing.
...It is simply a collaboration if you are willing.<br /><br />We can help and write a paper (ISI), including Numerical parts and also analytical.<br />In effect it seems that solving of this PDE and relevanted initial conditions is too hard for me. I tried but couldn't....<br /><br />Please let me know, what do you think about collaboration in this project?Mohammadhttps://www.blogger.com/profile/12765617084693177981noreply@blogger.comtag:blogger.com,1999:blog-5822805028291837738.post-4529813931113349312009-11-24T13:03:03.527-05:002009-11-24T13:03:03.527-05:00I don't have time to debug your code. If you ...I don't have time to debug your code. If you break the solution up into chunks and unit test those chunks, then you probably won't need me to look at your code because you will have located the problem yourself.<br /><br />I'd be happy to help once you identify a specific "part" that is broken, and you aren't sure how to fix it. Finding the broken part is a useful experience for you, and I wouldn't want to rob you of it.Joshua Stultshttps://www.blogger.com/profile/03506970399027046387noreply@blogger.comtag:blogger.com,1999:blog-5822805028291837738.post-40493855471401704882009-11-24T12:38:32.427-05:002009-11-24T12:38:32.427-05:00What sort of discretization did you use? What doe...What sort of discretization did you use? What does the discrete system matrix (or expression) that you came up with look like?<br /><br />The Thomas algorithm (Gaussian elimination for a tridiagonal system) only works for a 1-D problem. You'll have to use relaxation or some other iterative method; or if the problem is small enough just get Matlab to solve the system for you (this is easiest when you are learning). <br /><br />Once you have inverted the small problem directly with Matlab, then you can check that your iterative code is giving (roughly) the same answer.<br /><br />The other tip I would give you is to break up your solution into components that can be tested individually. <br /><br />Write a routine that calculates your forcing function, and test that it is operating correctly. <br /><br />Write a routine that calculates the derivatives, and test that it is operating correctly. <br /><br />Write a routine that takes the forcing function and derivatives and performs your chosen iterative update, and test that it is operating correctly. For example, you can check to see that it converges to the "direct" solution that Matlab gave you.<br /><br />If you follow this sort of methodical approach you should be able to locate which part of your solution method (derivative calculation, forcing function, iterative update) is incorrect.Joshua Stultshttps://www.blogger.com/profile/03506970399027046387noreply@blogger.comtag:blogger.com,1999:blog-5822805028291837738.post-77647986401867499332009-11-24T11:57:43.895-05:002009-11-24T11:57:43.895-05:00@Mohammad: "I had some questions about partia...@Mohammad: "I had some questions about partial differential equation in two dimensions..."<br /><br />Just post your question; that way other folks can benefit from the discussion. There's probably plenty of folks who have the same or similar questions.<br /><br />2-D simplifies things a bit so they are good example problems to talk about.<br /><br />Fire away...Joshua Stultshttps://www.blogger.com/profile/03506970399027046387noreply@blogger.comtag:blogger.com,1999:blog-5822805028291837738.post-5016496163478931022009-11-24T10:29:18.208-05:002009-11-24T10:29:18.208-05:00Dear jstults,
Hi,
Hope all is fine with you.
I...Dear jstults,<br /><br />Hi,<br /> <br />Hope all is fine with you.<br /><br />In the first I'm very thankfull for your really valuable materials about solving Poisson's equation in three dimensions, numeerically.<br /><br />I had some questions about partial differential equation in two dimensions but couldn't find your email.<br /><br />Would you mind Mail me via Phymalidoust@gmail.com for more discussions, please?<br /><br />I eagerly waiting your response.<br /><br />Bests,<br />MohammadMohammadhttps://www.blogger.com/profile/12765617084693177981noreply@blogger.comtag:blogger.com,1999:blog-5822805028291837738.post-2181439936143222362009-03-30T12:21:00.000-04:002009-03-30T12:21:00.000-04:00Neat page about adaptive mesh refinement (AMR) for...<A HREF="https://seesar.lbl.gov/anag/staff/martin/AMRPoisson.html" REL="nofollow">Neat page about adaptive mesh refinement (AMR) for Poisson's equation</A>.Joshua Stultshttps://www.blogger.com/profile/03506970399027046387noreply@blogger.com