Sort subset of Kokkos::DynamicView

[bathmatt]

I need to be able to get a subview of a dynamic view. Here is my use case

  Kokkos::Experimental::DynamicView<Vector3*> x_;
...
  Sorter.sort(Kokkos::subview(x_, reduced_size));

[hcedwar]

Subviews are problematic. However, sorting a subrange was added a while ago.
See https://github.com/kokkos/kokkos/blob/develop/algorithms/unit_tests/TestSort.hpp#L234
where the sort function can be given a [begin,end) range.
Hopefully that is sufficient.

[bathmatt]

I'm guessing I'm missing something

  KeyViewType local_ielement = Kokkos::subview(element_, reduced_size);

  Kokkos::BinSort<KeyViewType , BinOp > Sorter(local_ielement,binner,false);
  Sorter.create_permute_vector();
  Sorter.sort< KeyViewType >(local_ielement);
  Sorter.sort(x_, 0, reduced_size);

and it fails on the sort of x.

/home/mbetten/Trilinos/EMPIRE/src/PIC/ParticleContainer.cpp: In member function ‘void empire::pic::ParticleContainer::sort()’:
/home/mbetten/Trilinos/EMPIRE/src/PIC/ParticleContainer.cpp:92:34: error: no matching function for call to ‘Kokkos::BinSort<Kokkos::View<int*, Kokkos::OpenMP>, Kokkos::BinOp1D<Kokkos::View<int*, Kokkos::OpenMP> > >::sort(Kokkos::Experimental::DynamicView<empire::ConstLenVector<double, 3u>*>&, int, Kokkos::pair<long unsigned int, long unsigned int>&)’
   Sorter.sort(x_, 0, reduced_size);

[bathmatt]

Is it that the KeyViewType needs to be a dynamic view as well?

[hcedwar]

Not required.
I had implemented the sort function with DynamicView for you:
https://github.com/kokkos/kokkos/blob/master/algorithms/src/Kokkos_Sort.hpp#L524
However, it does not appear to cover your use case of sorting key array and applying permutation to value array. Perhaps the linked implementation shows enough of the pieces to code your use case?

[bathmatt]

Huh, not sure I understand this comment.

I need to apply the permutation to a lot of views. Are you saying I can do what I need to with kokkos the way it is or I need to redo my algorithm?

[hcedwar]

Can you copy & modify
https://github.com/kokkos/kokkos/blob/master/algorithms/src/Kokkos_Sort.hpp#L524
to implement what you need?

[bathmatt]

So, this code you do this bit of code.

  bin_sort.create_permute_vector();
  bin_sort.sort(view);

I thought you mentioned that I can't use that second function with ranges.

So, I guess I'm not smart enough to figure out what you're asking to do. Can I grab one of the guys who understands this and help work through all this/?

[bathmatt]

Here is my base data class

I need to make all of these dynamic views

  Kokkos::View<LocalOrdinal*> element_;
  Kokkos::View<Vector3*> x_;
  Kokkos::View<Vector3*> x_ref_;
  Kokkos::View<Vector3*> v_;
  Kokkos::View<Vector3*> v_ref_;
  Kokkos::View<Vector3*> E_, B_;
  

and then I sort them

 typedef Kokkos::View<LocalOrdinal*, PHX::Device> KeyViewType;
  typedef Kokkos::BinOp1D< KeyViewType > BinOp;


  int max_elems = MapContainer::getElementMap()->getNodeNumElements();
  int min_elems = 0, num_elems = max_elems-min_elems+1;
  BinOp binner(num_elems, min_elems, max_elems);

  Kokkos::pair<size_t, size_t> reduced_size(0,size());
  KeyViewType local_ielement = Kokkos::subview(element_, reduced_size);

  Kokkos::BinSort<KeyViewType , BinOp > Sorter(local_ielement,binner,false);
  Sorter.create_permute_vector();
  Sorter.sort< KeyViewType >(local_ielement);

  Sorter.sort(Kokkos::subview(x_, reduced_size));
  Sorter.sort(Kokkos::subview(x_ref_, reduced_size));
  Sorter.sort(Kokkos::subview(v_, reduced_size));
  Sorter.sort(Kokkos::subview(v_ref_, reduced_size));
  Sorter.sort(Kokkos::subview(E_, reduced_size));
  Sorter.sort(Kokkos::subview(B_, reduced_size));
  Sorter.sort(Kokkos::subview(weight_, reduced_size));

[hcedwar]

Desired API along the lines of:

BinSort<...> Sorter(element_, pair<int,int>(begin,end), binner, false );
Sorter.sort( x_ , pair<int,int>(begin,end) );
// etc.