questions about hyper-reduction and masking

[gokhalen]

Hello,

1. What is the difference between hyper-reduction and masking? Which one is more efficient? I think it is hyper-reduction.

2. Is there a demo of hyper-reduction available? I'm interested in a demo corresponding to the following link

https://pressio.github.io/pressio4py/html/md_pages_components_rom_lspg_hypred.html

3. Where can I browse the source? I can't find source corresponding to , let's say,
   pressio4py.rom.lspg.unsteady.HypredProblem

Thanks in advance,

Nachiket

[fnrizzi]

Hello,

1. What is the difference between hyper-reduction and masking? Which one is more efficient? I think it is hyper-reduction.

masking is just a trick to have the behavior of hyperreduction but without the difficulties of hyperreduction. Basically masking still uses the full FOM and only applies a filter to select specific elements.

2. Is there a demo of hyper-reduction available? I'm interested in a demo corresponding to the following link

Unfortunately there is not one.
We don't have resources at the moment to revise pressio4py.
However we do have a hyperreduction example in our tutorials but that uses c++ , see this: https://pressio.github.io/pressio-tutorials/endtoend/swe_lspg_hypred_1.html. but keep in mind this uses the c++ code that is more updated than pressio4py

3. Where can I browse the source? I can't find source corresponding to , let's say,

pressio4py.rom.lspg.unsteady.HypredProblem

here is the source: https://github.com/Pressio/pressio4py/blob/main/src/lspg_unsteady.hpp
You have to read c++ code since the prssio4py is just binding the c++ code.
not sure how clear this is to you. This code should greatly simplify if we had the time to update pressio4py to use the latest c++ version but right now we don't have the bandwidth

[fnrizzi]

I am away from my laptop so I will reply more later when I get to it

[gokhalen]

Thank you very much.

[fnrizzi]

@gokhalen i updated the comment above