Ngs-special-functions and pip

Installation & Troubleshooting
,
1

I have installed NGSolve on a Mac using pip and all is working well. But I would like to use
ngs-special-functions
I got the code from GitHub but it would not compile (which makes sense since I have no build folders for NGSolve). Is there any way to get access to special functions when NGSolve is installed via pip? I want to use Hankel functions in a scattering code.

Thanks!

2

Hi Peter,

it should work with the pip installer. It installs the ngsolve header files as well.
Make sure to rerun cmake after re-installung ngsolve, or updating the xcode compiler.

What are the errors you get ?

Joachim

3

Hi Peter,

It’s possible to get it running with the pip version, you just need to point CMake to the right directories.
To find out, where netgen/ngsolve is installed, run

python3 -c "import ngsolve; print(ngsolve.__file__)"

In my case, that’s /Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/ngsolve/__init__.py

Now take the directory above and add ‘cmake’, this is where CMake finds the build configuration (same applies for netgen).
The final build call looks like this:

[code]git clone GitHub - NGSolve/ngs-special-functions: Add special functions of SLATEC (http://www.netlib.org/slatec/) to NGSolve
cd ngs-special-functions
mkdir build
cd build

cmake …
-DNGSolve_DIR=/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/ngsolve/cmake
-DNetgen_DIR=/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/netgen/cmake
make -j4[/code]

Make sure to run cmake in an empty directory (remove files created by cmake before), otherwise the install dir is not set correctly.

Best,
Matthias

4

Hi Joachim, thanks for looking into this.

I worked on this some more and I see the header files that cmake is looking for in/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/ngsolve/cmake/NGSolveConfig.cmake
/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/netgen/cmake

so I tried

export CMAKE_PREFIX_PATH=“/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages:/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/netgen:${CMAKE_PREFIX_PATH}”
cmake …
make -j4

make ran OK but I got this error message from make

make -j4
[ 4%] Performing update step for ‘project_f2c’
[ 8%] No patch step for ‘project_f2c’
[ 12%] Performing configure step for ‘project_f2c’

Consolidate compiler generated dependencies of target special_functions[100%] Built target special_functions
Install the project…
– Install configuration: “Release”
CMake Error at cmake_install.cmake:41 (file):
file cannot create directory: /usr/local/ngsolve. Maybe need administrative privileges.
make[3]: *** [install] Error 1
make[2]: *** [project_ngsolve_specialcfs-prefix/src/project_ngsolve_specialcfs-stamp/project_ngsolve_specialcfs-install] Error 2
make[1]: *** [CMakeFiles/project_ngsolve_specialcfs.dir/all] Error 2
make: *** [all] Error 2

5

My post overlapped yours Matthias. I will do as you instruct. Thanks!

6

The error you got at the end is what I mentioned with the install directory. Just start in a clean directory and it should work.

Best,
Matthias

7

Thanks very much! Building in a clean download of the package using your instructions worked perfectly.