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ex1.c: Test star forest communication (PetscSF)\n\n
ex2.c: Test SF cuda stream synchronization in device to host communication\n\n
ex3.c: Test PetscSFFetchAndOp on patterned SF graphs
ex4.c: Test PetscSFFCompose when the ilocal array is not the identity\n\n
ex5.c: Test PetscSFFCompose when the ilocal arrays are not identity nor dense\n\n
ex6.c: Test VecScatter with x, y on different communicators\n\n
ex7.c: Test vecscatter of different block sizes across processes\n\n
ex8.c: Test VecScatterCreateToZero, VecScatterCreateToAll\n\n
ex9.c: This example shows 1) how to transfer vectors from a parent communicator to vectors on a child communicator and vice versa;\n\
ex11.c: Scatters between parallel vectors
ex12.c: Scatters from a parallel vector to a sequential vector
ex13.c: Scatters from a sequential vector to a parallel vector
ex14.c: Test event log of VecScatter with various block sizes\n\n
ex15.c: Test VecScatterRemap() on various vecscatter
ex16.c: Test PetscSFCreateByMatchingIndices\n\n
ex17.c: Test PetscSF with MPI large count (more than 2 billion elements in messages)\n\n
ex18.c: Test PetscSFConcatenate()\n\n
ex19.c: Test leaf sorting in PetscSFSetGraph()\n\n
ex20.c: PetscSF Ping-pong test to measure MPI latency\n\n
ex21.c: Test VecScatterCopy() on an SF with duplicated leaves \n\n
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