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<DIV>Dear All:</DIV>
<DIV> </DIV>
<DIV>Thank you all for your kindly help in pylith using. As a Pylith user,
here I want to offer</DIV>
<DIV>some suggestions from my experience of Pylith learning and using.</DIV>
<DIV> </DIV>
<DIV>Firstly, Pylith is a very useful software for simulation of co- and
post-seismic deformation</DIV>
<DIV>which can consider different earth model. Secondly, All of the Pylith
developers are very </DIV>
<DIV>kind in helping the users. </DIV>
<DIV> </DIV>
<DIV>However, I still think that the Pylith is not
very convenient for geo-scientists to use. </DIV>
<DIV>One important reason, in my opinion, perhaps is the complexity and
difficult of the mesh </DIV>
<DIV>construction. As to real problem with intricate fault geometry and earth
structure, the mesh</DIV>
<DIV>construction will take much time and general the user can not
generate perfect mesh. </DIV>
<DIV>This limits the wide use of Pylith to a great extent.</DIV>
<DIV> </DIV>
<DIV> For users we want to pay more attention on the scientific problems
itself ,not the tools </DIV>
<DIV>though it is also very important. So, I don't know if you can add
another function: mesh</DIV>
<DIV>construction. In fact, I think it is not very difficult for you
because the procedure is similar</DIV>
<DIV>for different model (earthquake).</DIV>
<DIV> </DIV>
<DIV>For example, recently I use Pylith to model
the co-seismic deformation of 2008 Mw7.9 Wenchuan</DIV>
<DIV>earthquake and the 2011 Mw9.0 Japan earthquake, by considering the
real earth structure, and </DIV>
<DIV>invert the slip distribution with 3D Green function. If one of
you are interested in this problem,</DIV>
<DIV>we can make a cooperation. I do the simulation ,inversion and analysis, and
you construct </DIV>
<DIV>the mesh. In addition, you can make cooperation with
scientist over the world who use Pylith.</DIV>
<DIV> </DIV>
<DIV>Here is just my hope and suggestions, and I reckon on your support !</DIV>
<DIV> </DIV>
<DIV>Best wishes,</DIV>
<DIV> </DIV>
<DIV>Faqi</DIV>
<DIV> </DIV>
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<DIV><B>发件人：</B> <A href="mailto:baagaard@usgs.gov">Brad Aagaard</A></DIV>
<DIV><B>发送时间：</B> 2011-11-02 09:55</DIV>
<DIV><B>收件人：</B> <A
href="mailto:faqidiao@asch.whigg.ac.cn">faqidiao</A></DIV>
<DIV><B>抄送：</B> <A href="mailto:willic3@gmail.com">Charles Williams</A>; <A
href="mailto:knepley@mcs.anl.gov">Matthew Knepley</A>; <A
href="mailto:faqidiao@gmail.com">faqidiao</A></DIV>
<DIV><B>主题：</B> Re: [CIG-SHORT] An error when running Pylith
.</DIV></DIV></DIV>
<DIV>
<DIV>Faqi,</DIV>
<DIV> </DIV>
<DIV>Following up on Charles's comment. You may have nearly coincident points</DIV>
<DIV>in your mesh that LaGriT is connecting together, resulting in slivers</DIV>
<DIV>elements. You may want to try removing coincident points and see if that</DIV>
<DIV>removes all of the bad cells. If you still have bad cells, then use some</DIV>
<DIV>of the other mesh quality tools to improve the mesh. The minimum aspect</DIV>
<DIV>ratio in LaGriT should be about 0.2 or larger (ParaView uses the inverse</DIV>
<DIV>so with it you want an aspect ratio less than about 5).</DIV>
<DIV> </DIV>
<DIV>Brad</DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>On 11/01/2011 06:03 PM, Charles Williams wrote:</DIV>
<DIV>> Hi Faqi,</DIV>
<DIV>> </DIV>
<DIV>> After looking at your mesh, the problem appears to be extremely poor mesh</DIV>
<DIV>> quality at the fault. In the attached figure, I calculated the mesh quality</DIV>
<DIV>> using ParaView, and then thresholded to show the really bad elements. There are</DIV>
<DIV>> a bunch of elements with essentially zero thickness right on the fault. Note</DIV>
<DIV>> that I created this by outputting the mesh in AVS format and looking at it in</DIV>
<DIV>> ParaView, but you can also check the mesh quality in LaGriT. Try improving the</DIV>
<DIV>> mesh quality and see what happens.</DIV>
<DIV>> </DIV>
<DIV>> Cheers,</DIV>
<DIV>> Charles</DIV>
<DIV>> </DIV>
<DIV>> [see attached file: wc_mesh_quality.jpg]</DIV>
<DIV>> </DIV>
<DIV>> On 1/11/2011, at 8:37 PM, faqidiao wrote:</DIV>
<DIV>> </DIV>
<DIV>>> Dear all:</DIV>
<DIV>>> I try to solve my problem following your suggestions. However, the error still</DIV>
<DIV>>> exist.</DIV>
<DIV>>> This time I construct a simple fault mesh with no curvature and just a single</DIV>
<DIV>>> fault.</DIV>
<DIV>>> I have checked my model again and again and did not find where the problem is.</DIV>
<DIV>>> Without any other way, I have to ask for your help again. Attached is my model,</DIV>
<DIV>>> I don't know if you have time checking my model. In addition, please have a check</DIV>
<DIV>>> of my 'cfg' file at the same time.</DIV>
<DIV>>> Thank you all again.</DIV>
<DIV>>> Best wishes,</DIV>
<DIV>>> Faqi</DIV>
<DIV>>> --------------------------------------------------------------------------------</DIV>
<DIV>>> *From:* Charles Williams<mailto:willic3@gmail.com></DIV>
<DIV>>> *Date:* 2011-10-27 03:49</DIV>
<DIV>>> *To:* Matthew Knepley<mailto:knepley@mcs.anl.gov></DIV>
<DIV>>> *CC:* faqidiao<mailto:faqidiao@asch.whigg.ac.cn>;faqidiao</DIV>
<DIV>>> <mailto:faqidiao@gmail.com>;cig-short<mailto:cig-short@geodynamics.org></DIV>
<DIV>>> *Subject:* Re: [CIG-SHORT] An error when running Pylith .</DIV>
<DIV>>> It can also happen if there is too much fault curvature. For this to happen,</DIV>
<DIV>>> there must be 3 faces on the fault, which means pretty extreme curvature or</DIV>
<DIV>>> your cell size is not fine enough for the fault geometry you are representing.</DIV>
<DIV>>></DIV>
<DIV>>> Charles</DIV>
<DIV>>></DIV>
<DIV>>></DIV>
<DIV>>> On 27/10/2011, at 4:29 AM, Matthew Knepley wrote:</DIV>
<DIV>>></DIV>
<DIV>>>> On Wed, Oct 26, 2011 at 10:13 AM, faqidiao<faqidiao@asch.whigg.ac.cn</DIV>
<DIV>>>> <mailto:faqidiao@asch.whigg.ac.cn>>wrote:</DIV>
<DIV>>>></DIV>
<DIV>>>> __</DIV>
<DIV>>>> Brad,</DIV>
<DIV>>>> Thanks for your rapid response. I try my problem with new version</DIV>
<DIV>>>> (pylith-1.6.1). However, error still occurred.</DIV>
<DIV>>>> Please find the attached error information. I agree with you, this</DIV>
<DIV>>>> perhaps induced by the fault topology. BUT,</DIV>
<DIV>>>> I have checked my Lagrit running and it's result , all seems well. So, I</DIV>
<DIV>>>> still puzzled about this.</DIV>
<DIV>>>> I also attached my problem, and I don't know whether you have time to run</DIV>
<DIV>>>> my model and check where the</DIV>
<DIV>>>> problem is?</DIV>
<DIV>>>></DIV>
<DIV>>>></DIV>
<DIV>>>> Here is the problem. Somewhere in your mesh, there is a terahedron with all 4</DIV>
<DIV>>>> vertices on a fault. This can happen</DIV>
<DIV>>>> because</DIV>
<DIV>>>></DIV>
<DIV>>>> a) there is a problem in your fault description</DIV>
<DIV>>>></DIV>
<DIV>>>> b) You have two faults which get too close to each other</DIV>
<DIV>>>></DIV>
<DIV>>>> Thanks,</DIV>
<DIV>>>></DIV>
<DIV>>>> Matt</DIV>
<DIV>>>></DIV>
<DIV>>>> Thank you again!</DIV>
<DIV>>>> Faqi Diao</DIV>
<DIV>>>> --------------------------------------------------------------------------------</DIV>
<DIV>>>> *From:* Brad Aagaard<mailto:baagaard@usgs.gov></DIV>
<DIV>>>> *Date:* 2011-10-26 12:45</DIV>
<DIV>>>> *To:* faqidiao<mailto:faqidiao@asch.whigg.ac.cn></DIV>
<DIV>>>> *CC:* cig-short<mailto:cig-short@geodynamics.org></DIV>
<DIV>>>> *Subject:* Re: [CIG-SHORT] An error when running Pylith .</DIV>
<DIV>>>> Faqi,</DIV>
<DIV>>>> The error message suggests that the nodeset/pset you are using to create</DIV>
<DIV>>>> the fault has a problem. This can happen if the fault has holes in it or</DIV>
<DIV>>>> there is a problem with the topology of the mesh. Another possibility is</DIV>
<DIV>>>> that there is a bug. We have made a lot of improvements since v1.4.2, so</DIV>
<DIV>>>> I recommend that you use the current release (v.1.6.1) and see if you</DIV>
<DIV>>>> still get the same error message.</DIV>
<DIV>>>> Regards,</DIV>
<DIV>>>> Brad</DIV>
<DIV>>>> -----faqidiao<faqidiao@asch.whigg.ac.cn</DIV>
<DIV>>>> <mailto:faqidiao@asch.whigg.ac.cn>> wrote: -----</DIV>
<DIV>>>> =======================</DIV>
<DIV>>>> To: cig-short<cig-short@geodynamics.org<mailto:cig-short@geodynamics.org>></DIV>
<DIV>>>> From: faqidiao<faqidiao@asch.whigg.ac.cn<mailto:faqidiao@asch.whigg.ac.cn>></DIV>
<DIV>>>> Date: 10/25/2011 07:07PM</DIV>
<DIV>>>> Subject: [CIG-SHORT] An error when running Pylith .</DIV>
<DIV>>>> =======================</DIV>
<DIV>>>> Hi all,</DIV>
<DIV>>>> Recently, I met a problem when running Pylith1.4.2, and I don't know how</DIV>
<DIV>>>> to fix</DIV>
<DIV>>>> it, though I have paid much time.</DIV>
<DIV>>>> Attached is the error message, can you have a look and give some suggestions</DIV>
<DIV>>>> on how to solve the problem?</DIV>
<DIV>>>> Thank you in advance!</DIV>
<DIV>>>> Best regards,</DIV>
<DIV>>>> Faqi Diao_______________________________________________</DIV>
<DIV>>>> CIG-SHORT mailing list</DIV>
<DIV>>>> CIG-SHORT@geodynamics.org<mailto:CIG-SHORT@geodynamics.org></DIV>
<DIV>>>> http://geodynamics.org/cgi-bin/mailman/listinfo/cig-short</DIV>
<DIV>>>> [attachment(s) "error message.png" removed by Brad Aagaard/GD/USGS/DOI]=</DIV>
<DIV>>>></DIV>
<DIV>>>> _______________________________________________</DIV>
<DIV>>>> CIG-SHORT mailing list</DIV>
<DIV>>>> CIG-SHORT@geodynamics.org<mailto:CIG-SHORT@geodynamics.org></DIV>
<DIV>>>> http://geodynamics.org/cgi-bin/mailman/listinfo/cig-short</DIV>
<DIV>>>></DIV>
<DIV>>>></DIV>
<DIV>>>></DIV>
<DIV>>>></DIV>
<DIV>>>> --</DIV>
<DIV>>>> What most experimenters take for granted before they begin their experiments</DIV>
<DIV>>>> is infinitely more interesting than any results to which their experiments lead.</DIV>
<DIV>>>> -- Norbert Wiener</DIV>
<DIV>>>> _______________________________________________</DIV>
<DIV>>>> CIG-SHORT mailing list</DIV>
<DIV>>>> CIG-SHORT@geodynamics.org<mailto:CIG-SHORT@geodynamics.org></DIV>
<DIV>>>> http://geodynamics.org/cgi-bin/mailman/listinfo/cig-short</DIV>
<DIV>>></DIV>
<DIV>>> Charles A. Williams</DIV>
<DIV>>> Scientist</DIV>
<DIV>>> GNS Science</DIV>
<DIV>>> 1 Fairway Drive, Avalon</DIV>
<DIV>>> PO Box 30368</DIV>
<DIV>>> Lower Hutt 5040</DIV>
<DIV>>> New Zealand</DIV>
<DIV>>> ph (office): 0064-4570-4566</DIV>
<DIV>>> fax (office): 0064-4570-4600</DIV>
<DIV>>> C.Williams@gns.cri.nz<mailto:C.Williams@gns.cri.nz></DIV>
<DIV>>></DIV>
<DIV>>> <wenc-test.zip><readme.doc><error message.png></DIV>
<DIV>> </DIV>
<DIV>> Charles A. Williams</DIV>
<DIV>> Scientist</DIV>
<DIV>> GNS Science</DIV>
<DIV>> 1 Fairway Drive, Avalon</DIV>
<DIV>> PO Box 30368</DIV>
<DIV>> Lower Hutt 5040</DIV>
<DIV>> New Zealand</DIV>
<DIV>> ph (office): 0064-4570-4566</DIV>
<DIV>> fax (office): 0064-4570-4600</DIV>
<DIV>> C.Williams@gns.cri.nz<mailto:C.Williams@gns.cri.nz></DIV>
<DIV>> </DIV>
<DIV> </DIV></DIV></BODY></HTML>