Use the coodinate DA. Matt
On Fri, Aug 28, 2009 at 2:54 AM, nicolas aunai <nicolas.aunai at gmail.com>wrote: > Hi, > > Hum... Yes and no. This function does indeed create a VectorScatter > that allows to go from parallel to sequential and natural vectors, but > the sequential vectors must but structured to receive the DA data. For > example a 2D DA with 3 degree of freedom will require a specific > vector with a global size equal to nx*ny*3 > > I want to scatter the coordinates vector obtained with the function > DAGetCoordinates(), which is of size nx*ny*2. > > This is the reason why I was not using the DACreateNaturalVector() > function and then VecScatterCreateToZero(), the natural vector being > created has a wrong size. > > > > > > 2009/8/27 Matthew Knepley <knepley at gmail.com>: > > This should be good enough > > > > > > > http://www.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-current/docs/manualpages/DA/DAGlobalToNaturalAllCreate.html > > > > Matt > > > > On Thu, Aug 27, 2009 at 12:51 PM, nicolas aunai <nicolas.aunai at gmail.com > > > > wrote: > >> > >> Hello, > >> > >> > >> I have a problem using 'VecScatterCreateToZero'. I attach to this > >> email a test code that illustrates the problem. I create a 2D DA then > >> I ask for the coordinates (that have been set just before), which are > >> returned in a global vector. I want to write the coordinates in a > >> file, so I use 'VecScatterCreateToZero' to put all the values in > >> sequential vector. It seems to work fine but sometimes (depending on > >> the number of proc used) the coordinates in the sequential vectors are > >> ordered differently. > >> > >> to run the code and see the problem : > >> > >> mpiexec -n 4 ./vecdacoord > problem.txt > >> > >> I have attached problem.txt too. > >> > >> Is someone can explain to me how I could obtain my coordinates in a > >> natural order ? > >> > >> > >> Thx > > > > > > > > -- > > What most experimenters take for granted before they begin their > experiments > > is infinitely more interesting than any results to which their > experiments > > lead. > > -- Norbert Wiener > > > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20090828/7f8b7ec8/attachment-0001.htm>
