Installation

Install the mhn package using pip

Since the mhn package is largely written in Cython, a Cython-supported C compiler, such as GCC or MSVC, must be installed on your device before you can install this package.
If that is the case, you can simply install the mhn package using pip:

pip install mhn

If the installation of mhn was successful, you should be able to import it with

import mhn

Use the CUDA implementation to accelerate computations

If your device has an Nvidia GPU, you can accelerate the computation of the log-likelihood and its gradient for both the full and the restricted state space with CUDA. For that you have to have CUDA and the CUDA compiler installed on your device. You can check that in the terminal with

nvcc --version

If this command is recognized, then CUDA should be installed on your device. During installation the package will automatically check if the CUDA compiler is installed on your device and will enable the corresponding functions if this is the case. While running a Python script you can test if the mhn package has access to GPU-accelerated functions using the cuda_available() function as shown below:

import mhn

print(mhn.cuda_available())

# the three possible results are also available as constants:
# CUDA_AVAILABLE, CUDA_NOT_AVAILABLE, CUDA_NOT_FUNCTIONAL

if mhn.cuda_available() == mhn.CUDA_AVAILABLE:
    print('CUDA is available')

if mhn.cuda_available() == mhn.CUDA_NOT_AVAILABLE:
    print('CUDA compiler nvcc was not present during installation')

if mhn.cuda_available() == mhn.CUDA_NOT_FUNCTIONAL:
    print('CUDA compiler nvcc available but CUDA functions not working. Check CUDA installation')

Pay special attention to the CUDA_NOT_FUNCTIONAL case. This indicates that while the CUDA compiler is installed, basic functionalities like GPU memory allocation are not working as expected. This likely points to an issue with your CUDA drivers, so you should verify your CUDA installation.

If you cannot resolve CUDA_NOT_FUNCTIONAL by changing CUDA drivers, we recommend to install the package with CPU support only. This can be accomplished on Linux via

export INSTALL_MHN_NO_CUDA=1
pip install mhn

and on Windows via

set INSTALL_MHN_NO_CUDA=1
pip install mhn

If you installed nvcc after installing the mhn package, you have to reinstall this package to gain access to the CUDA functions.

Reinstalling the package for CUDA-related reasons

If you want to reinstall the package because you want to either enable or disable CUDA support, you should add the --no-cache-dir flag during installation to ensure that pip does not use a cached version of the package and that the package is actually recompiled:

pip uninstall mhn
pip install mhn --no-cache-dir