Re: [petsc-users] Kronecker Product
The matrix can be a shell matrix, only the matrix-vector product operation is required. Jose > El 30 ene 2023, a las 22:23, Guglielmo, Tyler Hardy via petsc-users > escribió: > > I have an implementation of the slepc MFN matrix exponential which is > implicitly using ExpoKit. You have to supply a matrix into the Slepc MFN > operator to set the problem up as far as I know. > > Tyler > > From: Matthew Knepley > Date: Monday, January 30, 2023 at 12:24 PM > To: Guglielmo, Tyler Hardy > Cc: Barry Smith , petsc-users@mcs.anl.gov > > Subject: Re: [petsc-users] Kronecker Product > > On Mon, Jan 30, 2023 at 3:08 PM Guglielmo, Tyler Hardy via petsc-users > wrote: > I would need the Kronecker product to be explicitly available to perform > matrix exponentials. A and B are of order 5000, so not too large. I will > give storing them on all ranks a shot. Thanks for the tips! > > Were you going to do exponentials by explicit factorization? For large > matrices, I thought it was common to > use matrix-free methods > (https://slepc.upv.es/documentation/current/docs/manualpages/MFN/index.html) > > Thanks, > > Matt > > > Best, > Tyler > > From: Barry Smith > Date: Monday, January 30, 2023 at 12:01 PM > To: Guglielmo, Tyler Hardy > Cc: petsc-users@mcs.anl.gov > Subject: Re: [petsc-users] Kronecker Product > > > What is large? If A and B have dimensions of 1000, then the Kronecker > product is of size 1,000,000. Do you want the Kronecker product to be > explicitly formed or just available as matrix vector products? If just > explicitly available then I think you can just store sparse A (for example) > completely on all ranks, 10,000 by 10,000 sparse matrix is small for > sequential) while B is distributed. > > Barry > > > > On Jan 30, 2023, at 2:48 PM, Guglielmo, Tyler Hardy > wrote: > > Both matrices (A and B) would be approximately the same size and large. The > use case (for me at least) is to create several large sparse matrices which > will be combined in various ways through Kronecker products. The combination > happens at every time step in an evolution, so it really needs to be fast as > well. I’m thinking mpi/petsc is probably not the most optimal way for > dealing with this, and might just have to work with single node > multi-threading. > > Best, > Tyler > > From: Matthew Knepley > Date: Monday, January 30, 2023 at 11:31 AM > To: Guglielmo, Tyler Hardy > Cc: Barry Smith , petsc-users@mcs.anl.gov > > Subject: Re: [petsc-users] Kronecker Product > > On Mon, Jan 30, 2023 at 2:24 PM Guglielmo, Tyler Hardy via petsc-users > wrote: > Thanks Barry, > > I saw that function, but wasn’t sure how to apply it since the documentation > says that S and T are dense matrices, but in my case all matrices involved > are sparse. Is there a way to work around the dense requirement? > > We don't have parallel sparse-sparse. It would not be too hard to write, but > it would be some work. > > It is hard to understand the use case. Is one matrix much smaller? If not, > and you inherit the distribution from A, it seems > like it might be very suboptimal, and otherwise you would have to > redistribute on the fly and it would get very complicated. > > Thanks, > > Matt > > Best, > Tyler > > From: Barry Smith > Date: Monday, January 30, 2023 at 11:12 AM > To: Guglielmo, Tyler Hardy > Cc: petsc-users@mcs.anl.gov > Subject: Re: [petsc-users] Kronecker Product > > >Do you need the explicit sparse representation of the Kronecker product? > Or do you want to apply it as an operator or solve systems with it? If the > latter you can use > https://petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/#matcreatekaij > > Barry > > > > > > On Jan 30, 2023, at 12:53 PM, Guglielmo, Tyler Hardy via petsc-users > wrote: > > Hi all, > > I am wondering if there is any functionality for taking Kronecker products of > large sparse matrices that are parallel? MatSeqAIJKron is as close as I have > found, but it seems like this does not work for parallel matrices. Any ideas > here? > > An option could be to make A and B sequential, compute the Kronecker product, > C, then scatter C into a parallel matrix? This seems like a horribly > inefficient procedure. I’m still fairly new to petsc, so thanks for patience > :)! > > Best, > Tyler > > + > Tyler Guglielmo > Postdoctoral Researcher > Lawrence Livermore National Lab > Office: 925-423-6186 > Cell: 210-480-8000
Re: [petsc-users] Kronecker Product
I have an implementation of the slepc MFN matrix exponential which is implicitly using ExpoKit. You have to supply a matrix into the Slepc MFN operator to set the problem up as far as I know. Tyler From: Matthew Knepley Date: Monday, January 30, 2023 at 12:24 PM To: Guglielmo, Tyler Hardy Cc: Barry Smith , petsc-users@mcs.anl.gov Subject: Re: [petsc-users] Kronecker Product On Mon, Jan 30, 2023 at 3:08 PM Guglielmo, Tyler Hardy via petsc-users mailto:petsc-users@mcs.anl.gov>> wrote: I would need the Kronecker product to be explicitly available to perform matrix exponentials. A and B are of order 5000, so not too large. I will give storing them on all ranks a shot. Thanks for the tips! Were you going to do exponentials by explicit factorization? For large matrices, I thought it was common to use matrix-free methods (https://slepc.upv.es/documentation/current/docs/manualpages/MFN/index.html<https://urldefense.us/v3/__https:/slepc.upv.es/documentation/current/docs/manualpages/MFN/index.html__;!!G2kpM7uM-TzIFchu!nSXMSWur4Lrpt0oF_bjtBae92VccTBcCHUQJRYWByuB4bZ5HHzFHhGtLjs7NrgHZUCE$>) Thanks, Matt Best, Tyler From: Barry Smith mailto:bsm...@petsc.dev>> Date: Monday, January 30, 2023 at 12:01 PM To: Guglielmo, Tyler Hardy mailto:gugliel...@llnl.gov>> Cc: petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov> mailto:petsc-users@mcs.anl.gov>> Subject: Re: [petsc-users] Kronecker Product What is large? If A and B have dimensions of 1000, then the Kronecker product is of size 1,000,000. Do you want the Kronecker product to be explicitly formed or just available as matrix vector products? If just explicitly available then I think you can just store sparse A (for example) completely on all ranks, 10,000 by 10,000 sparse matrix is small for sequential) while B is distributed. Barry On Jan 30, 2023, at 2:48 PM, Guglielmo, Tyler Hardy mailto:gugliel...@llnl.gov>> wrote: Both matrices (A and B) would be approximately the same size and large. The use case (for me at least) is to create several large sparse matrices which will be combined in various ways through Kronecker products. The combination happens at every time step in an evolution, so it really needs to be fast as well. I’m thinking mpi/petsc is probably not the most optimal way for dealing with this, and might just have to work with single node multi-threading. Best, Tyler From: Matthew Knepley mailto:knep...@gmail.com>> Date: Monday, January 30, 2023 at 11:31 AM To: Guglielmo, Tyler Hardy mailto:gugliel...@llnl.gov>> Cc: Barry Smith mailto:bsm...@petsc.dev>>, petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov> mailto:petsc-users@mcs.anl.gov>> Subject: Re: [petsc-users] Kronecker Product On Mon, Jan 30, 2023 at 2:24 PM Guglielmo, Tyler Hardy via petsc-users mailto:petsc-users@mcs.anl.gov>> wrote: Thanks Barry, I saw that function, but wasn’t sure how to apply it since the documentation says that S and T are dense matrices, but in my case all matrices involved are sparse. Is there a way to work around the dense requirement? We don't have parallel sparse-sparse. It would not be too hard to write, but it would be some work. It is hard to understand the use case. Is one matrix much smaller? If not, and you inherit the distribution from A, it seems like it might be very suboptimal, and otherwise you would have to redistribute on the fly and it would get very complicated. Thanks, Matt Best, Tyler From: Barry Smith mailto:bsm...@petsc.dev>> Date: Monday, January 30, 2023 at 11:12 AM To: Guglielmo, Tyler Hardy mailto:gugliel...@llnl.gov>> Cc: petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov> mailto:petsc-users@mcs.anl.gov>> Subject: Re: [petsc-users] Kronecker Product Do you need the explicit sparse representation of the Kronecker product? Or do you want to apply it as an operator or solve systems with it? If the latter you can use https://petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/#matcreatekaij<https://urldefense.us/v3/__https:/petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/*matcreatekaij__;Iw!!G2kpM7uM-TzIFchu!lSQ9WFlYi6PMdfs3WAfEq4ydgCLZtfDgyFy9PjdLNTisCsHtwmVuukcpIv1J0i1EtiQ$> Barry On Jan 30, 2023, at 12:53 PM, Guglielmo, Tyler Hardy via petsc-users mailto:petsc-users@mcs.anl.gov>> wrote: Hi all, I am wondering if there is any functionality for taking Kronecker products of large sparse matrices that are parallel? MatSeqAIJKron is as close as I have found, but it seems like this does not work for parallel matrices. Any ideas here? An option could be to make A and B sequential, compute the Kronecker product, C, then scatter C into a parallel matrix? This seems like a horribly inefficient procedure. I’m still fairly new to petsc, so thanks for patience :)! Best, Tyler +++
Re: [petsc-users] Kronecker Product
On Mon, Jan 30, 2023 at 3:08 PM Guglielmo, Tyler Hardy via petsc-users < petsc-users@mcs.anl.gov> wrote: > I would need the Kronecker product to be explicitly available to perform > matrix exponentials. A and B are of order 5000, so not too large. I will > give storing them on all ranks a shot. Thanks for the tips! > Were you going to do exponentials by explicit factorization? For large matrices, I thought it was common to use matrix-free methods ( https://slepc.upv.es/documentation/current/docs/manualpages/MFN/index.html) Thanks, Matt > > > Best, > > Tyler > > > > *From: *Barry Smith > *Date: *Monday, January 30, 2023 at 12:01 PM > *To: *Guglielmo, Tyler Hardy > *Cc: *petsc-users@mcs.anl.gov > *Subject: *Re: [petsc-users] Kronecker Product > > > > What is large? If A and B have dimensions of 1000, then the Kronecker > product is of size 1,000,000. Do you want the Kronecker product to be > explicitly formed or just available as matrix vector products? If just > explicitly available then I think you can just store sparse A (for example) > completely on all ranks, 10,000 by 10,000 sparse matrix is small for > sequential) while B is distributed. > > > > Barry > > > > > > On Jan 30, 2023, at 2:48 PM, Guglielmo, Tyler Hardy > wrote: > > > > Both matrices (A and B) would be approximately the same size and large. > The use case (for me at least) is to create several large sparse matrices > which will be combined in various ways through Kronecker products. The > combination happens at every time step in an evolution, so it really needs > to be fast as well. I’m thinking mpi/petsc is probably not the most > optimal way for dealing with this, and might just have to work with single > node multi-threading. > > > > Best, > > Tyler > > > > *From: *Matthew Knepley > *Date: *Monday, January 30, 2023 at 11:31 AM > *To: *Guglielmo, Tyler Hardy > *Cc: *Barry Smith , petsc-users@mcs.anl.gov < > petsc-users@mcs.anl.gov> > *Subject: *Re: [petsc-users] Kronecker Product > > On Mon, Jan 30, 2023 at 2:24 PM Guglielmo, Tyler Hardy via petsc-users < > petsc-users@mcs.anl.gov> wrote: > > Thanks Barry, > > > > I saw that function, but wasn’t sure how to apply it since the > documentation says that S and T are dense matrices, but in my case all > matrices involved are sparse. Is there a way to work around the dense > requirement? > > > > We don't have parallel sparse-sparse. It would not be too hard to write, > but it would be some work. > > > > It is hard to understand the use case. Is one matrix much smaller? If not, > and you inherit the distribution from A, it seems > > like it might be very suboptimal, and otherwise you would have to > redistribute on the fly and it would get very complicated. > > > > Thanks, > > > > Matt > > > > Best, > > Tyler > > > > *From: *Barry Smith > *Date: *Monday, January 30, 2023 at 11:12 AM > *To: *Guglielmo, Tyler Hardy > *Cc: *petsc-users@mcs.anl.gov > *Subject: *Re: [petsc-users] Kronecker Product > > > >Do you need the explicit sparse representation of the Kronecker > product? Or do you want to apply it as an operator or solve systems with > it? If the latter you can use > https://petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/#matcreatekaij > <https://urldefense.us/v3/__https:/petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/*matcreatekaij__;Iw!!G2kpM7uM-TzIFchu!lSQ9WFlYi6PMdfs3WAfEq4ydgCLZtfDgyFy9PjdLNTisCsHtwmVuukcpIv1J0i1EtiQ$> > > > > Barry > > > > > > > > On Jan 30, 2023, at 12:53 PM, Guglielmo, Tyler Hardy via petsc-users < > petsc-users@mcs.anl.gov> wrote: > > > > Hi all, > > > > I am wondering if there is any functionality for taking Kronecker products > of large sparse matrices that are parallel? MatSeqAIJKron is as close as I > have found, but it seems like this does not work for parallel matrices. > Any ideas here? > > > > An option could be to make A and B sequential, compute the Kronecker > product, C, then scatter C into a parallel matrix? This seems like a > horribly inefficient procedure. I’m still fairly new to petsc, so thanks > for patience :)! > > > > Best, > > Tyler > > > > + > > Tyler Guglielmo > > Postdoctoral Researcher > > Lawrence Livermore National Lab > > Office: 925-423-6186 > > Cell: 210-480-8000 > > + > > > > > > > -- > > What most experimenters take for granted before they begin their > expe
Re: [petsc-users] Kronecker Product
I would need the Kronecker product to be explicitly available to perform matrix exponentials. A and B are of order 5000, so not too large. I will give storing them on all ranks a shot. Thanks for the tips! Best, Tyler From: Barry Smith Date: Monday, January 30, 2023 at 12:01 PM To: Guglielmo, Tyler Hardy Cc: petsc-users@mcs.anl.gov Subject: Re: [petsc-users] Kronecker Product What is large? If A and B have dimensions of 1000, then the Kronecker product is of size 1,000,000. Do you want the Kronecker product to be explicitly formed or just available as matrix vector products? If just explicitly available then I think you can just store sparse A (for example) completely on all ranks, 10,000 by 10,000 sparse matrix is small for sequential) while B is distributed. Barry On Jan 30, 2023, at 2:48 PM, Guglielmo, Tyler Hardy wrote: Both matrices (A and B) would be approximately the same size and large. The use case (for me at least) is to create several large sparse matrices which will be combined in various ways through Kronecker products. The combination happens at every time step in an evolution, so it really needs to be fast as well. I’m thinking mpi/petsc is probably not the most optimal way for dealing with this, and might just have to work with single node multi-threading. Best, Tyler From: Matthew Knepley mailto:knep...@gmail.com>> Date: Monday, January 30, 2023 at 11:31 AM To: Guglielmo, Tyler Hardy mailto:gugliel...@llnl.gov>> Cc: Barry Smith mailto:bsm...@petsc.dev>>, petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov> mailto:petsc-users@mcs.anl.gov>> Subject: Re: [petsc-users] Kronecker Product On Mon, Jan 30, 2023 at 2:24 PM Guglielmo, Tyler Hardy via petsc-users mailto:petsc-users@mcs.anl.gov>> wrote: Thanks Barry, I saw that function, but wasn’t sure how to apply it since the documentation says that S and T are dense matrices, but in my case all matrices involved are sparse. Is there a way to work around the dense requirement? We don't have parallel sparse-sparse. It would not be too hard to write, but it would be some work. It is hard to understand the use case. Is one matrix much smaller? If not, and you inherit the distribution from A, it seems like it might be very suboptimal, and otherwise you would have to redistribute on the fly and it would get very complicated. Thanks, Matt Best, Tyler From: Barry Smith mailto:bsm...@petsc.dev>> Date: Monday, January 30, 2023 at 11:12 AM To: Guglielmo, Tyler Hardy mailto:gugliel...@llnl.gov>> Cc: petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov> mailto:petsc-users@mcs.anl.gov>> Subject: Re: [petsc-users] Kronecker Product Do you need the explicit sparse representation of the Kronecker product? Or do you want to apply it as an operator or solve systems with it? If the latter you can use https://petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/#matcreatekaij<https://urldefense.us/v3/__https:/petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/*matcreatekaij__;Iw!!G2kpM7uM-TzIFchu!lSQ9WFlYi6PMdfs3WAfEq4ydgCLZtfDgyFy9PjdLNTisCsHtwmVuukcpIv1J0i1EtiQ$> Barry On Jan 30, 2023, at 12:53 PM, Guglielmo, Tyler Hardy via petsc-users mailto:petsc-users@mcs.anl.gov>> wrote: Hi all, I am wondering if there is any functionality for taking Kronecker products of large sparse matrices that are parallel? MatSeqAIJKron is as close as I have found, but it seems like this does not work for parallel matrices. Any ideas here? An option could be to make A and B sequential, compute the Kronecker product, C, then scatter C into a parallel matrix? This seems like a horribly inefficient procedure. I’m still fairly new to petsc, so thanks for patience :)! Best, Tyler + Tyler Guglielmo Postdoctoral Researcher Lawrence Livermore National Lab Office: 925-423-6186 Cell: 210-480-8000 + -- 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 https://www.cse.buffalo.edu/~knepley/<https://urldefense.us/v3/__http:/www.cse.buffalo.edu/*knepley/__;fg!!G2kpM7uM-TzIFchu!nK03nUENfNtHoOs8RWmJWJQYJH2IlC_lYQPNn7kV9FsBv2CQKR_VSqbLGRLFShVpKmY$>
Re: [petsc-users] Kronecker Product
What is large? If A and B have dimensions of 1000, then the Kronecker product is of size 1,000,000. Do you want the Kronecker product to be explicitly formed or just available as matrix vector products? If just explicitly available then I think you can just store sparse A (for example) completely on all ranks, 10,000 by 10,000 sparse matrix is small for sequential) while B is distributed. Barry > On Jan 30, 2023, at 2:48 PM, Guglielmo, Tyler Hardy > wrote: > > Both matrices (A and B) would be approximately the same size and large. The > use case (for me at least) is to create several large sparse matrices which > will be combined in various ways through Kronecker products. The combination > happens at every time step in an evolution, so it really needs to be fast as > well. I’m thinking mpi/petsc is probably not the most optimal way for > dealing with this, and might just have to work with single node > multi-threading. > > Best, > Tyler > > From: Matthew Knepley mailto:knep...@gmail.com>> > Date: Monday, January 30, 2023 at 11:31 AM > To: Guglielmo, Tyler Hardy mailto:gugliel...@llnl.gov>> > Cc: Barry Smith mailto:bsm...@petsc.dev>>, > petsc-users@mcs.anl.gov <mailto:petsc-users@mcs.anl.gov> > mailto:petsc-users@mcs.anl.gov>> > Subject: Re: [petsc-users] Kronecker Product > > On Mon, Jan 30, 2023 at 2:24 PM Guglielmo, Tyler Hardy via petsc-users > mailto:petsc-users@mcs.anl.gov>> wrote: > Thanks Barry, > > I saw that function, but wasn’t sure how to apply it since the documentation > says that S and T are dense matrices, but in my case all matrices involved > are sparse. Is there a way to work around the dense requirement? > > We don't have parallel sparse-sparse. It would not be too hard to write, but > it would be some work. > > It is hard to understand the use case. Is one matrix much smaller? If not, > and you inherit the distribution from A, it seems > like it might be very suboptimal, and otherwise you would have to > redistribute on the fly and it would get very complicated. > > Thanks, > > Matt > > Best, > Tyler > > From: Barry Smith mailto:bsm...@petsc.dev>> > Date: Monday, January 30, 2023 at 11:12 AM > To: Guglielmo, Tyler Hardy mailto:gugliel...@llnl.gov>> > Cc: petsc-users@mcs.anl.gov <mailto:petsc-users@mcs.anl.gov> > mailto:petsc-users@mcs.anl.gov>> > Subject: Re: [petsc-users] Kronecker Product > > >Do you need the explicit sparse representation of the Kronecker product? > Or do you want to apply it as an operator or solve systems with it? If the > latter you can use > https://petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/#matcreatekaij > <https://urldefense.us/v3/__https:/petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/*matcreatekaij__;Iw!!G2kpM7uM-TzIFchu!lSQ9WFlYi6PMdfs3WAfEq4ydgCLZtfDgyFy9PjdLNTisCsHtwmVuukcpIv1J0i1EtiQ$> > > Barry > > > > > > On Jan 30, 2023, at 12:53 PM, Guglielmo, Tyler Hardy via petsc-users > mailto:petsc-users@mcs.anl.gov>> wrote: > > Hi all, > > I am wondering if there is any functionality for taking Kronecker products of > large sparse matrices that are parallel? MatSeqAIJKron is as close as I have > found, but it seems like this does not work for parallel matrices. Any ideas > here? > > An option could be to make A and B sequential, compute the Kronecker product, > C, then scatter C into a parallel matrix? This seems like a horribly > inefficient procedure. I’m still fairly new to petsc, so thanks for patience > :)! > > Best, > Tyler > > + > Tyler Guglielmo > Postdoctoral Researcher > Lawrence Livermore National Lab > Office: 925-423-6186 > Cell: 210-480-8000 > + > > > > -- > 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 > > https://www.cse.buffalo.edu/~knepley/ > <https://urldefense.us/v3/__http:/www.cse.buffalo.edu/*knepley/__;fg!!G2kpM7uM-TzIFchu!nK03nUENfNtHoOs8RWmJWJQYJH2IlC_lYQPNn7kV9FsBv2CQKR_VSqbLGRLFShVpKmY$>
Re: [petsc-users] Kronecker Product
Both matrices (A and B) would be approximately the same size and large. The use case (for me at least) is to create several large sparse matrices which will be combined in various ways through Kronecker products. The combination happens at every time step in an evolution, so it really needs to be fast as well. I’m thinking mpi/petsc is probably not the most optimal way for dealing with this, and might just have to work with single node multi-threading. Best, Tyler From: Matthew Knepley Date: Monday, January 30, 2023 at 11:31 AM To: Guglielmo, Tyler Hardy Cc: Barry Smith , petsc-users@mcs.anl.gov Subject: Re: [petsc-users] Kronecker Product On Mon, Jan 30, 2023 at 2:24 PM Guglielmo, Tyler Hardy via petsc-users mailto:petsc-users@mcs.anl.gov>> wrote: Thanks Barry, I saw that function, but wasn’t sure how to apply it since the documentation says that S and T are dense matrices, but in my case all matrices involved are sparse. Is there a way to work around the dense requirement? We don't have parallel sparse-sparse. It would not be too hard to write, but it would be some work. It is hard to understand the use case. Is one matrix much smaller? If not, and you inherit the distribution from A, it seems like it might be very suboptimal, and otherwise you would have to redistribute on the fly and it would get very complicated. Thanks, Matt Best, Tyler From: Barry Smith mailto:bsm...@petsc.dev>> Date: Monday, January 30, 2023 at 11:12 AM To: Guglielmo, Tyler Hardy mailto:gugliel...@llnl.gov>> Cc: petsc-users@mcs.anl.gov<mailto:petsc-users@mcs.anl.gov> mailto:petsc-users@mcs.anl.gov>> Subject: Re: [petsc-users] Kronecker Product Do you need the explicit sparse representation of the Kronecker product? Or do you want to apply it as an operator or solve systems with it? If the latter you can use https://petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/#matcreatekaij<https://urldefense.us/v3/__https:/petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/*matcreatekaij__;Iw!!G2kpM7uM-TzIFchu!lSQ9WFlYi6PMdfs3WAfEq4ydgCLZtfDgyFy9PjdLNTisCsHtwmVuukcpIv1J0i1EtiQ$> Barry On Jan 30, 2023, at 12:53 PM, Guglielmo, Tyler Hardy via petsc-users mailto:petsc-users@mcs.anl.gov>> wrote: Hi all, I am wondering if there is any functionality for taking Kronecker products of large sparse matrices that are parallel? MatSeqAIJKron is as close as I have found, but it seems like this does not work for parallel matrices. Any ideas here? An option could be to make A and B sequential, compute the Kronecker product, C, then scatter C into a parallel matrix? This seems like a horribly inefficient procedure. I’m still fairly new to petsc, so thanks for patience :)! Best, Tyler + Tyler Guglielmo Postdoctoral Researcher Lawrence Livermore National Lab Office: 925-423-6186 Cell: 210-480-8000 + -- 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 https://www.cse.buffalo.edu/~knepley/<https://urldefense.us/v3/__http:/www.cse.buffalo.edu/*knepley/__;fg!!G2kpM7uM-TzIFchu!nK03nUENfNtHoOs8RWmJWJQYJH2IlC_lYQPNn7kV9FsBv2CQKR_VSqbLGRLFShVpKmY$>
Re: [petsc-users] Kronecker Product
On Mon, Jan 30, 2023 at 2:24 PM Guglielmo, Tyler Hardy via petsc-users < petsc-users@mcs.anl.gov> wrote: > Thanks Barry, > > > > I saw that function, but wasn’t sure how to apply it since the > documentation says that S and T are dense matrices, but in my case all > matrices involved are sparse. Is there a way to work around the dense > requirement? > We don't have parallel sparse-sparse. It would not be too hard to write, but it would be some work. It is hard to understand the use case. Is one matrix much smaller? If not, and you inherit the distribution from A, it seems like it might be very suboptimal, and otherwise you would have to redistribute on the fly and it would get very complicated. Thanks, Matt > Best, > > Tyler > > > > *From: *Barry Smith > *Date: *Monday, January 30, 2023 at 11:12 AM > *To: *Guglielmo, Tyler Hardy > *Cc: *petsc-users@mcs.anl.gov > *Subject: *Re: [petsc-users] Kronecker Product > > > >Do you need the explicit sparse representation of the Kronecker > product? Or do you want to apply it as an operator or solve systems with > it? If the latter you can use > https://petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/#matcreatekaij > <https://urldefense.us/v3/__https:/petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/*matcreatekaij__;Iw!!G2kpM7uM-TzIFchu!lSQ9WFlYi6PMdfs3WAfEq4ydgCLZtfDgyFy9PjdLNTisCsHtwmVuukcpIv1J0i1EtiQ$> > > > > Barry > > > > > > > > On Jan 30, 2023, at 12:53 PM, Guglielmo, Tyler Hardy via petsc-users < > petsc-users@mcs.anl.gov> wrote: > > > > Hi all, > > > > I am wondering if there is any functionality for taking Kronecker products > of large sparse matrices that are parallel? MatSeqAIJKron is as close as I > have found, but it seems like this does not work for parallel matrices. > Any ideas here? > > > > An option could be to make A and B sequential, compute the Kronecker > product, C, then scatter C into a parallel matrix? This seems like a > horribly inefficient procedure. I’m still fairly new to petsc, so thanks > for patience :)! > > > > Best, > > Tyler > > > > + > > Tyler Guglielmo > > Postdoctoral Researcher > > Lawrence Livermore National Lab > > Office: 925-423-6186 > > Cell: 210-480-8000 > > + > > > -- 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 https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>
Re: [petsc-users] Kronecker Product
Thanks Barry, I saw that function, but wasn’t sure how to apply it since the documentation says that S and T are dense matrices, but in my case all matrices involved are sparse. Is there a way to work around the dense requirement? Best, Tyler From: Barry Smith Date: Monday, January 30, 2023 at 11:12 AM To: Guglielmo, Tyler Hardy Cc: petsc-users@mcs.anl.gov Subject: Re: [petsc-users] Kronecker Product Do you need the explicit sparse representation of the Kronecker product? Or do you want to apply it as an operator or solve systems with it? If the latter you can use https://petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/#matcreatekaij<https://urldefense.us/v3/__https:/petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/*matcreatekaij__;Iw!!G2kpM7uM-TzIFchu!lSQ9WFlYi6PMdfs3WAfEq4ydgCLZtfDgyFy9PjdLNTisCsHtwmVuukcpIv1J0i1EtiQ$> Barry On Jan 30, 2023, at 12:53 PM, Guglielmo, Tyler Hardy via petsc-users wrote: Hi all, I am wondering if there is any functionality for taking Kronecker products of large sparse matrices that are parallel? MatSeqAIJKron is as close as I have found, but it seems like this does not work for parallel matrices. Any ideas here? An option could be to make A and B sequential, compute the Kronecker product, C, then scatter C into a parallel matrix? This seems like a horribly inefficient procedure. I’m still fairly new to petsc, so thanks for patience :)! Best, Tyler + Tyler Guglielmo Postdoctoral Researcher Lawrence Livermore National Lab Office: 925-423-6186 Cell: 210-480-8000 +
Re: [petsc-users] Kronecker Product
Do you need the explicit sparse representation of the Kronecker product? Or do you want to apply it as an operator or solve systems with it? If the latter you can use https://petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/#matcreatekaij Barry > On Jan 30, 2023, at 12:53 PM, Guglielmo, Tyler Hardy via petsc-users > wrote: > > Hi all, > > I am wondering if there is any functionality for taking Kronecker products of > large sparse matrices that are parallel? MatSeqAIJKron is as close as I have > found, but it seems like this does not work for parallel matrices. Any ideas > here? > > An option could be to make A and B sequential, compute the Kronecker product, > C, then scatter C into a parallel matrix? This seems like a horribly > inefficient procedure. I’m still fairly new to petsc, so thanks for patience > :)! > > Best, > Tyler > > + > Tyler Guglielmo > Postdoctoral Researcher > Lawrence Livermore National Lab > Office: 925-423-6186 > Cell: 210-480-8000 > +
[petsc-users] Kronecker Product
Hi all, I am wondering if there is any functionality for taking Kronecker products of large sparse matrices that are parallel? MatSeqAIJKron is as close as I have found, but it seems like this does not work for parallel matrices. Any ideas here? An option could be to make A and B sequential, compute the Kronecker product, C, then scatter C into a parallel matrix? This seems like a horribly inefficient procedure. I’m still fairly new to petsc, so thanks for patience :)! Best, Tyler + Tyler Guglielmo Postdoctoral Researcher Lawrence Livermore National Lab Office: 925-423-6186 Cell: 210-480-8000 +
[petsc-users] Kronecker product
Hello team, I'd like to ask whether PETSc has a function to compute the Kronecker product of a sparse matrix with an identity matrix? A Google search didn't lead me to a manual page (like most of the other PETSc functions), so I'm wondering if this has been implemented yet. Thanks very much! Best, Yuyun
Re: [petsc-users] Kronecker product
MatCreateMAIJ does that (implicitly). https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Mat/MatCreateMAIJ.html If you want a Kronecker product with a non-identity matrix, this PR may be of interest. https://bitbucket.org/petsc/petsc/pull-requests/1334/rmills-mat-kaij/diff Yuyun Yang via petsc-users writes: > Hello team, > > I'd like to ask whether PETSc has a function to compute the Kronecker product > of a sparse matrix with an identity matrix? A Google search didn't lead me to > a manual page (like most of the other PETSc functions), so I'm wondering if > this has been implemented yet. > > Thanks very much! > > Best, > Yuyun
