Calling a C++ Library in .udf file

[raj-brown]

Dear All-
I am trying to call an external C++ library win .udf file but while import .h files It complains that I can not fine it. Although I compiled nekRS by adding include dir and linking the library. Still It could not find .h files. Could you please help me with this.

Thanks!
Raj

[stgeke]

The udf file is JIT compiled, so adding the include s+ libs when building nekRS won't work.
Please define the following env-vars to make it work:

NEKRS_UDF_INCLUDES for optional include directories ("/path1/foo1;/path2/foo2")
NEKRS_UDF_LIBS for optional libraries ("/path1/lib1.so;/path2/lib2.so")

[raj-brown]

@stgeke One question: The include env-var will work if include directory has a lost of subdirs?

[raj-brown]

hi @stgeke I tried defining library and include files via environment variables but it did not work.

[stgeke]

Make sure to use latest next.

[raj-brown]

@stgeke I did not get, what is next.

[stgeke]

The next branch instead of the default (master).

[raj-brown]

@stgeke will you have a quick 10 mnts? I can show you the error

[raj-brown]

Hi @stgeke I tried next branch and it did not work either.

[raj-brown]

Hi @stgeke when i run an example from next branch it gives the following errors
'''
/users/kshukla1/.local/nekrs/include/elliptic/elliptic.h:159:10: fatal error: ellipticMultiGrid.h: No such file or directory
159 | #include "ellipticMultiGrid.h"
| ^~~~~~~~~~~~~~~~~~~~~
'''
Could you please help me with this.

[stgeke]

What example are we talking about?

[raj-brown]

I was running turbPipe

[stgeke]

Running turbPipe fails even if you don't set NEKRS_UDF_INCLUDES ?

[raj-brown]

Yes! without modifying UDF_INCLUDES

[stgeke]

Did you remove the build and installation dir before building the latest next branch?

[raj-brown]

yes..i did from scratch

[stgeke]

Does ellipticMultiGrid.h exist in the installation directory?

[raj-brown]

yes
but it is in MG folder

[raj-brown]

Hi @stgeke Do I need to change something in CMAke?

[raj-brown]

Hi @stgeke I was able to build the next branch and ran an existing example successfully...but defining UDF_INCLUDE did not work.Any suggestion would be really helpful..Thanks!

[stgeke]

Can you please post how you defined NEKRS_UDF_INCLUDES.

[raj-brown]

Hi Stefan @stgeke if you have time for a quick zoom then that will be really helpful. I also wanted to discuss about this paper of yours https://arxiv.org/pdf/2409.06404. Thank you very much!

[stgeke]

Please DM me.

[raj-brown]

Thanks Stefan @stgeke.Could you please provide me your email id. Thank you!

[stgeke]

You'll find it here: https://nek5000.mcs.anl.gov/

…

On Tue, Sep 17, 2024 at 2:44 PM raj-brown ***@***.***> wrote: Thanks Stefan @stgeke.Could you please provide me your email id. Thank you! — Reply to this email directly, view it on GitHub <#585 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AEN2M75DZDQYMICV6JWSA3TZXAP2RAVCNFSM6AAAAABOB4GLPGVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTANRXGAZDOMI> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[raj-brown]

Hi @stgeke I just ent you email..

[raj-brown]

Hi @stgeke this is how I define the INCLUDE neviron-

export NEKRS_UDF_INCLUDES=$NEKRS_UDF_INCLUDES:/oscar/data/gk/kshukla1/CFD_NEKRS/nekRS/3rd_party/pytorch/libtorch/include

[stgeke]

Please try

export NEKRS_UDF_INCLUDES=/oscar/data/gk/kshukla1/CFD_NEKRS/nekRS/3rd_party/pytorch/libtorch/include

[stgeke]

Please also remove the udf cache

rm -rf .cache/udf

[raj-brown]

Hi @stgeke I just did and it did not work

In file included from /oscar/data/gk/kshukla1/CFD_NEKRS/nekRS/examples/turbPipe/.cache/udf/udf.cpp:7:
/oscar/data/gk/kshukla1/CFD_NEKRS/nekRS/examples/turbPipe/turbPipe.udf:4:10: fatal error: torch/torch.h: No such file or directory
    4 | #include "torch/torch.h"

[raj-brown]

Hi @stgeke This is the library which I want to call in .udf file..

https://download.pytorch.org/libtorch/nightly/cpu/libtorch-cxx11-abi-static-without-deps-1.9.0.dev20210516%2Bcpu.zip

[stgeke]

Hmm it works for me. Not sure what’s going on. Anyway you can also try to add a udf.cmake to your case directory defining custom includes and libs.

…

On Tue, 17 Sep 2024 at 15:15, raj-brown ***@***.***> wrote: Hi @stgeke <https://github.com/stgeke> I just did and it did not work In file included from /oscar/data/gk/kshukla1/CFD_NEKRS/nekRS/examples/turbPipe/.cache/udf/udf.cpp:7: /oscar/data/gk/kshukla1/CFD_NEKRS/nekRS/examples/turbPipe/turbPipe.udf:4:10: fatal error: torch/torch.h: No such file or directory 4 | #include "torch/torch.h" — Reply to this email directly, view it on GitHub <#585 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AEN2M73T3E5MRERUSXXUAWDZXATOXAVCNFSM6AAAAABOB4GLPGVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTANRXGA3DGMA> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[raj-brown]

Hi @stgeke you mean the torch library works for you.Could you please share your case file for .udf.

[stgeke]

No, I am talking about the general functionality.

[raj-brown]

hi @stgeke this is how i was able to call the library in other C++ library

FIND_PACKAGE(Torch REQUIRED)
SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${TORCH_CXX_FLAGS}")
TARGET_LINK_LIBRARIES(SolverUtils LINK_PUBLIC "${TORCH_LIBRARIES}")

[stgeke]

Sure, you can add something like this to udf.cmake

FIND_PACKAGE(Torch REQUIRED)
target_link_libraries(udf PUBLIC "${TORCH_LIBRARIES}")

[raj-brown]

Hi @stgeke It seems like it is working now as I included the .cmake files. I will have to test a couple of more things but I think Its okay now. Thank you Stefan! Also about nekCRF I have sent you an email..Thank you very much!

[raj-brown]

Hi @stgeke I was wondering if there is any example where boundary (essential and natural) conditions are varying with time? Thank you very much for your help.

[raj-brown]

Hi @stgeke Just wanted to check if you have any example where time dependent boundary condition is implemented. Thank you!

[stgeke]

Although I don't recall any examples that use a time-varying boundary condition, it is fully supported. You can simply access the time via bc->time within the boundary function of choice.