phi1.globalValue will return the value over the entire domain > On Aug 29, 2016, at 10:50 AM, ronghai wu <ronghai...@fau.de> wrote: > > > > On 29/08/16 15:06, Guyer, Jonathan E. Dr. (Fed) wrote: >> Hard to say. Diagnosing parallel race conditions is neither easy nor >> entertaining. >> >> Could be that you just need a comm.Barrier() call before the comm.bcast() >> calls. >> >> One possible issue is that FiPy automatically partitions the mesh when it >> detects that it is running in parallel, so the result of your run() routine >> is that phi1 gets solved only on partition 1, phi2 only on partition 2, etc. >> and so it may be waiting for the solutions on the other partitions that are >> never going to come. >> > > As I print the shape of phi1...phi4, I found the reason is that: I want to > solve four equations with each equation (in whole mesh) one core. However, > once running with $mpiexec -n 4 python script.py, Fipy will automatically > divide the mesh and cellvariables into four subdomains. Besides, it seems > that the user defined communicator cannot control fipy communicator. > Anyway, if I do not do any tricky thing, just write normal code and run in > four-core parallel, for example the following code: > > ############# > nx = > 200 > > ny = nx > dx = > 1. > > dy = > 1. > > mesh = fp.PeriodicGrid2D(nx=nx, ny=ny, dx=dx, dy=dy) > eq1 = fp.TransientTerm(var=phi1, coeff=1.) == fp.DiffusionTerm(var=phi1, > coeff=1. > ) > eq2 = fp.TransientTerm( > var=phi2, coeff=1.) == fp.DiffusionTerm(var=phi2, coeff=1. > ) > eq3 = fp.TransientTerm( > var=phi3, coeff=1.) == fp.DiffusionTerm(var=phi3, coeff=1. > ) > eq4 = fp.TransientTerm( > var=phi4, coeff=1.) == fp.DiffusionTerm(var=phi4, coeff=1. > ) > eq = eq1 & eq2 & eq3 & eq4 > res = > 1.e4 > > while res > 1.e-3 > : > eq.cacheMatrix() > eq.cacheRHSvector() > res = eq.sweep( > dt=1, solver > =solver()) > > mat > = eq.matrix > > vec > = eq.RHSvector > > phi1.updateOld() > phi2.updateOld() > phi3.updateOld() > phi4.updateOld() > > print 'phi1 shape = ' > , np.shape(phi1.value) > > > ############# I notice the np.shape(phi1.value) is not the whole mesh shape > (200*200), but (10400) ,(10400), (10800) and (10800) in four subdomains. The > question is, how to gather phi1 in subdomains to make it a complete one in > the whole domain (with shape 40000)? Thanks >>> On Aug 28, 2016, at 11:50 AM, ronghai wu <ronghai...@fau.de> >>> wrote: >>> >>> >>> Dear Fipy developers and users, >>> >>> The official parallel running way works for me, however, I would like to >>> try an different way shown in the attached script. When running by $time >>> mpiexec -n 4 python My_Fipy_Parallel.py, it gets stuck at time step 179 >>> without any error message pop out, four cores are full but enough memory >>> left. The bigger the mesh is, the sooner it will get stuck. Does any know >>> why and how to solve this problem? Thanks. >>> >>> Regards >>> Ronghai >>> <My_Fipy_Parallel.py>_______________________________________________ >>> fipy mailing list >>> >>> fipy@nist.gov >>> http://www.ctcms.nist.gov/fipy >>> >>> [ NIST internal ONLY: >>> https://email.nist.gov/mailman/listinfo/fipy >>> ] >>> >> >> _______________________________________________ >> fipy mailing list >> >> fipy@nist.gov >> http://www.ctcms.nist.gov/fipy >> >> [ NIST internal ONLY: >> https://email.nist.gov/mailman/listinfo/fipy >> ] >> > -- > ------------------------------------------ > Ronghai Wu > > Institute of Materials Simulation (WW8) > Department of Materials Science and Engineering > University of Erlangen-Nürnberg > Dr.-Mack-Str. 77, 90762 Fürth, Germany > > Tel. +49 (0)911 65078-65064 > > _______________________________________________ > fipy mailing list > fipy@nist.gov > http://www.ctcms.nist.gov/fipy > [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]
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