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<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US">Thank you Mark and Barry.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US"><a id="OWAAM3F9AFB4C861F014AACA86D8A70231CD5" href="mailto:mfadams@lbl.gov"><span style="font-family:"Calibri",sans-serif;text-decoration:none">@Mark Adams</span></a> I follow you
for the most part. Shouldn’t R be an MPI Vector?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US">Here it goes:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Q[Vec[i]] for all "i" in my local (sequential) "Vec".<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Compute number of local nonzeros in Q, call it n.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">//Create a MPI Vector R, with local size n<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="p1">VecCreate(PETSC_COMM_WORLD, &R); </p>
<p class="p1">VecSetType(R, VECMPI); </p>
<p class="p1">VecSetSizes(R, <b>n</b>, PETSC_DECIDE); </p>
<p class="p1"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">//Populate MPI Vector R with local (sequential) "Vec".<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="p1">VecGetOwnershipRange(R, &istart, &iend); </p>
<p class="p1">local_size = iend - istart; //The local_size should be ‘<b>n</b>’ right?</p>
<p class="p1">VecGetArray(R, &values); </p>
<p class="p1"><span class="apple-converted-space"> </span><span class="s1"><b>for</b></span> (i =
<span class="s2">0</span>; i < local_size; i++) {</p>
<p class="p1"><span class="apple-converted-space"> </span>values[i] = Vec[i];</p>
<p class="p1"><span class="apple-converted-space"> </span>}</p>
<p class="p1">VecRestoreArray(R, &values); </p>
<p class="p1"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">//Scatter R to all processors
<o:p></o:p></span></p>
<p class="p1"><o:p> </o:p></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:Menlo;color:black">Vec V_SEQ;<o:p></o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:Menlo;color:black">VecScatter ctx;<o:p></o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:Menlo;color:black"> <o:p></o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:Menlo;color:black">VecScatterCreateToAll(R,&ctx,&V_SEQ);<o:p></o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:Menlo;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:Menlo;color:black">//Remove duplicates in V_SEQ<o:p></o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:Menlo;color:black">How can I use PetscSortRemoveDupsInt to remove duplicates in V_SEQ?<o:p></o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:Menlo;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:Menlo;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:Menlo;color:black">Physics behind:<o:p></o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:Menlo;color:black">I am reading a parallel mesh, and want to mark all the boundary nodes. I use a local (sequential) Vec to store the boundary nodes for each parallel partition.
Hence, local Vecs can end up with duplicate node index among them, which I would like to get rid of when I combine all of them together.<o:p></o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:Menlo;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:Menlo;color:black">Best,<o:p></o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:Menlo;color:black">Karthik.<o:p></o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:Menlo;color:black"><o:p> </o:p></span></p>
<p class="p1"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><b><span style="font-size:12.0pt;color:black">From:
</span></b><span style="font-size:12.0pt;color:black">Mark Adams <mfadams@lbl.gov><br>
<b>Date: </b>Friday, 9 December 2022 at 21:08<br>
<b>To: </b>Chockalingam, Karthikeyan (STFC,DL,HC) <karthikeyan.chockalingam@stfc.ac.uk><br>
<b>Cc: </b>Barry Smith <bsmith@petsc.dev>, petsc-users@mcs.anl.gov <petsc-users@mcs.anl.gov><br>
<b>Subject: </b>Re: [petsc-users] Union of sequential vecs<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt">If your space is pretty compact, eg, (0,12), you could create an MPI vector Q of size 13, say, and each processor can add 1.0 to Q[Vec[i]], for all "i" in my local "Vec".<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt">Then each processor can count the number of local nonzeros in Q, call it n, create a new vector, R, with local size n, then set R[i] = global index of the nonzero for each nonzero in Q, i=0:n.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt">Do some sort of vec-scatter-to-all with R to get what you want.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt">Does that work?<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt">Mark<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt">On Fri, Dec 9, 2022 at 3:25 PM Karthikeyan Chockalingam - STFC UKRI via petsc-users <</span><a href="mailto:petsc-users@mcs.anl.gov"><span style="font-size:11.0pt">petsc-users@mcs.anl.gov</span></a><span style="font-size:11.0pt">>
wrote:<o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">That is where I am stuck,
<u>I don’t know</u> who to combine them to get Vec = {2,5,7,8,10,11,12}.<o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">I just want them in an MPI vector.<o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">I finally plan to call VecScatterCreateToAll so that all processor gets a copy.<o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">Thank you.<o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">Kind regards,<o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">Karthik.<o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:12.0pt"><b><span style="font-size:12.0pt;color:black">From:
</span></b><span style="font-size:12.0pt;color:black">Barry Smith <</span><a href="mailto:bsmith@petsc.dev" target="_blank"><span style="font-size:12.0pt">bsmith@petsc.dev</span></a><span style="font-size:12.0pt;color:black">><br>
<b>Date: </b>Friday, 9 December 2022 at 20:04<br>
<b>To: </b>Chockalingam, Karthikeyan (STFC,DL,HC) <</span><a href="mailto:karthikeyan.chockalingam@stfc.ac.uk" target="_blank"><span style="font-size:12.0pt">karthikeyan.chockalingam@stfc.ac.uk</span></a><span style="font-size:12.0pt;color:black">><br>
<b>Cc: </b></span><a href="mailto:petsc-users@mcs.anl.gov" target="_blank"><span style="font-size:12.0pt">petsc-users@mcs.anl.gov</span></a><span style="font-size:12.0pt;color:black"> <</span><a href="mailto:petsc-users@mcs.anl.gov" target="_blank"><span style="font-size:12.0pt">petsc-users@mcs.anl.gov</span></a><span style="font-size:12.0pt;color:black">><br>
<b>Subject: </b>Re: [petsc-users] Union of sequential vecs</span><span style="font-size:11.0pt"><o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> How are you combining them to get Vec = {2,5,7,8,10,11,12}?<o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> Do you want the values to remain on the same MPI rank as before, just in an MPI vector?<o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:12.0pt"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">On Dec 9, 2022, at 2:28 PM, Karthikeyan Chockalingam - STFC UKRI via petsc-users <</span><a href="mailto:petsc-users@mcs.anl.gov" target="_blank"><span style="font-size:11.0pt">petsc-users@mcs.anl.gov</span></a><span style="font-size:11.0pt">>
wrote:<o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">Hi,<o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">I want to take the union of a set of sequential vectors, each living in a different processor.<o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">Say,<span class="m5796220908723221417apple-converted-space"> </span><o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">Vec_Seq1 = {2,5,7}<o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">Vec_Seq2 = {5,8,10,11}<o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">Vec_Seq3 = {5,2,12}.<o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">Finally, get the union of all them Vec = {2,5,7,8,10,11,12}.<o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">I initially wanted to create a parallel vector and insert the (sequential vector) values but I do not know, to which index to insert the values to.
But I do know the total size of Vec (which in this case is 7).<o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">Any help is much appreciated.<o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">Kind regards,<o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt">Karthik.<o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
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