Installation MHKit 1.0.1 on Mac OS

[DwiNY2026]

I am able to install MHKit version 1.0.1 on Mac OS
However, I have a problem testing it; see errors below. Please help. Thanks

pyenv(Version="/opt/anaconda3/envs/mhkit/bin/python")

ans =

PythonEnvironment with properties:

      Version: "3.11"
   Executable: "/opt/anaconda3/envs/mhkit/bin/python"
      Library: "/opt/anaconda3/envs/mhkit/lib/libpython3.11.dylib"
         Home: "/opt/anaconda3/envs/mhkit"
       Status: NotLoaded
ExecutionMode: InProcess

[x, y] = circular(30)
Unable to resolve the name 'py.importlib.import_module'.

Error in circular (line 22)
py.importlib.import_module('mhkit');

[simmsa]

Hi @DwiNY2026, in MATLAB in the command window can you try setting ExecutionMode to OutOfProcess

pyenv(ExecutionMode="OutOfProcess")

And restart matlab and see if that helps.

If that doesn't help can you also print the version of MHKiT-Python you have installed to verify it is working correctly outside of MATLAB?

Please activate your conda environment in your terminal

conda activate mhkit

and run:

python -c "import mhkit; print(mhkit.__version__)"

python -c "import mhkit; print(mhkit.river.performance.circular(30))"

And let us know what those commands yield? This will help us determine the root cause.

This software is admittedly difficult to get MHKiT-MATLAB installed on MacOS, but I have a similar setup and can likely point you in the right direction.

[DwiNY2026]

Dear Andrew, Thank you for your help 1. Quitting MATLAB won't help 2. When running outside, Matlab works fine: [image: Screenshot 2026-03-18 at 3.22.58 PM.png] Thank you Dwi

…

On Wed, Mar 18, 2026 at 3:02 PM Andrew Simms ***@***.***> wrote: *simmsa* left a comment (MHKiT-Software/MHKiT-MATLAB#197) <#197 (comment)> Hi @DwiNY2026 <https://github.com/DwiNY2026>, in MATLAB in the command window can you try setting ExecutionMode to OutOfProcess pyenv(ExecutionMode="OutOfProcess") And restart matlab and see if that helps. If that doesn't help can you also print the version of MHKiT-Python you have installed to verify it is working correctly outside of MATLAB? Please activate your conda environment in your terminal conda activate mhkit and run: python -c "import mhkit; print(mhkit.__version__)" python -c "import mhkit; print(mhkit.river.performance.circular(30))" And let us know what those commands yield? This will help us determine the root cause. This software is admittedly difficult to get MHKiT-MATLAB installed on MacOS, but I have a similar setup and can likely point you in the right direction. — Reply to this email directly, view it on GitHub <#197 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/CAGO7PEMHTGACNVFXWYOPST4RLXGDAVCNFSM6AAAAACWW5HC26VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHM2DAOBUHE2DONRVGY> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[simmsa]

@DwiNY2026, I unfortunately cant see that screenshot?

Same error in MATLAB? What version of MATLAB to you have?

[DwiNY2026]

Oh may apology:

(base) Mac-mini:~ dwi$ conda activate mhkit
(mhkit) Mac-mini:~ dwi$ python -c "import mhkit; print(mhkit.version)"
v1.0.1
(mhkit) Mac-mini:~ dwi$ python -c "import mhkit; print(mhkit.river.performance.circular(30))"
(30, 706.8583470577034)
(mhkit) Mac-mini:~ dwi$

[DwiNY2026]

I used MATLAB 2023b. But if necessary, I can install the 2024 or 2025

[simmsa]

@DwiNY2026, that all looks good. Per this: https://github.com/MHKiT-Software/MHKiT-MATLAB?tab=readme-ov-file#software-requirements

You should be OK with matlab versions.

Did you install the latest mltbx file from here? https://github.com/MHKiT-Software/MHKiT-MATLAB/releases/tag/v1.0.1

Can you try some of the troubleshooting steps here:

https://www.mathworks.com/help/matlab/matlab_external/undefined-variable-py-or-function-py-command.html

This error indicates that python is not working properly in MATLAB:

[x, y] = circular(30)
Unable to resolve the name 'py.importlib.import_module'.

Which is one level "above" mhkit.

Does something like this work in your MATLAB command window:

l = py.list({'a', 'b', 'c'})

That will tell us if python is working at all in MATLAB.

[DwiNY2026]

I did not install from : Did you install the latest mltbx file from here? https://github.com/MHKiT-Software/MHKiT-MATLAB/releases/tag/v1.0.1
Ok, I will try it.

I used from the "git clone https://github.com/MHKiT-Software/MHKiT-MATLAB.git"

l = py.list({'a', 'b', 'c'})
Unable to resolve the name 'py.list'.

I will reinstall mltbx from your link
Thank you

[DwiNY2026]

1. Do I have to remove all files inside the MHKIT-MATLAB directory and download all zip files and put inside this directory?
2. Please guide me to install it.

[simmsa]

@DwiNY2026 This is the root cause of your problem:

l = py.list({'a', 'b', 'c'})
Unable to resolve the name 'py.list'.

The above error means that your version of MATLAB is not detecting python at all

I checked and this works on the latest version of MATLAB that I have installed locally, 2025b.

>> l = py.list({'a', 'b', 'c'})


l = 

  Python [list](matlab:helpPopup('py.list')) with values:

    ['a', 'b', 'c']

    Use string, double or cell function to convert to a MATLAB array.

>> pyenv

ans = 

  [PythonEnvironment](matlab:helpPopup('matlab.pyclient.PythonEnvironment')) with properties:

          Version: "3.11"
       Executable: "/opt/anaconda3/envs/mhkit-matlab-env/bin/python"
          Library: "/opt/anaconda3/envs/mhkit-matlab-env/lib/libpython3.11.dylib"
             Home: "/opt/anaconda3/envs/mhkit-matlab-env"
           Status: Loaded
    ExecutionMode: OutOfProcess
        ProcessID: "14759"
      ProcessName: "MATLABPyHost"


>> version

ans =

    '25.2.0.3042426 (R2025b) Update 1'

>>

It may be valuable for you to try this step again:

https://mhkit-software.github.io/MHKiT/matlab_installation.html#step-6-configure-matlab-python-environment

To verify that MATLAB "picked up" the anaconda version of python.

MATLAB is "picky" about python versioning installs. The documentation for pyenv is here: https://www.mathworks.com/help/matlab/ref/pyenv.html and this may have some clues for you also.

[simmsa]

Also, depending on your use case you may not need Python at all, as some modules are MATLAB native code.

What module/functions are you planning on using?

[DwiNY2026]

1. I don't mind reinstalling from the beginning. Originally, I used MATLAB 2005b, and I had the latest Python version, but then I had to downgrade because I had conflicting errors during the installation when following exactly the guideline.

2. Would you mind updating the guideline in
   https://mhkit-software.github.io/MHKiT/matlab_installation.html

Suppose I'm using MATLAB 2025b; what Python, NumPy, and SciPy versions do I have installed?
Especially, the commands below may need to be updated.

conda create -n mhkit python=3.10
pip install mhkit==0.7.0
pip install numpy~=1.24.0 scipy~=1.10.0 netcdf4~=1.6.0

[DwiNY2026]

I installed Matlab 2024b. It seems a small progress:

l = py.list({'a', 'b', 'c'})

l =

Python list with values:

['a', 'b', 'c']

Use string, double or cell function to convert to a MATLAB array.

[x, y] = circular(30)
Python Error: ImportError:
dlopen(/opt/anaconda3/envs/mhkit/lib/python3.11/site-packages/netCDF4/_netCDF4.cpython-311-darwin.so,
0x000A): Symbol not found: _SSL_get0_group_name
Referenced from: <9C5CC915-156B-36DB-8C78-45A97DF0BDC8> /opt/anaconda3/envs/mhkit/lib/libcurl.4.dylib
Expected in: <4447AD75-60CC-3855-8373-857D31DCFC1E>
/Applications/MATLAB_R2024b.app/bin/maci64/libssl.3.dylib

Error in circular (line 24)
result=py.mhkit.river.performance.circular(diameter);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

[simmsa]

I installed Matlab 2024b. It seems a small progress:

l = py.list({'a', 'b', 'c'})

l =

Python list with values:

['a', 'b', 'c']

Use string, double or cell function to convert to a MATLAB array.

[x, y] = circular(30)
Python Error: ImportError:
dlopen(/opt/anaconda3/envs/mhkit/lib/python3.11/site-packages/netCDF4/_netCDF4.cpython-311-darwin.so,
0x000A): Symbol not found: _SSL_get0_group_name
Referenced from: <9C5CC915-156B-36DB-8C78-45A97DF0BDC8> /opt/anaconda3/envs/mhkit/lib/libcurl.4.dylib
Expected in: <4447AD75-60CC-3855-8373-857D31DCFC1E>
/Applications/MATLAB_R2024b.app/bin/maci64/libssl.3.dylib

Error in circular (line 24) result=py.mhkit.river.performance.circular(diameter); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

@DwiNY2026, this is good progress. It looks like Python is working now.

The above is a MacOS specific error that I have dealt with before. It is a bit tricky as everyones computer is a bit different here.

In the mhkit conda environment can you try this step:

conda install openssl=="3.0.*"

And restart matlab and try that same command and paste in the result if it does not work?

These errors are specific Anaconda and MATLAB incompatibilities, that are not documented anywhere and require a bit of trial and error to actually fix.

[DwiNY2026]

As you suggested, in mhkit environment I run conda install openssl=="3.0.*" (mhkit) Mac-mini:~ dwi$ conda install openssl=="3.0.*" Channels: - defaults - conda-forge Platform: osx-64 Collecting package metadata (repodata.json): done Solving environment: done ## Package Plan ## environment location: /opt/anaconda3/envs/mhkit added / updated specs: - openssl=3.0 The following packages will be downloaded: package | build

---------------------------|----------------- cryptography-45.0.5 | py311hc0e11ad_0 1.6 MB curl-7.88.1 | h6df9250_0 140 KB conda-forge h5py-3.8.0 |nompi_py311h777de7a_100 1.0 MB conda-forge h5pyd-0.22.0 | pyhd8ed1ab_0 117 KB conda-forge hdf5-1.12.2 |nompi_h48135f9_101 3.0 MB conda-forge libcurl-7.88.1 | h6df9250_0 335 KB conda-forge libnetcdf-4.8.1 |nompi_hc61b76e_106 1.4 MB conda-forge libnghttp2-1.52.0 | he2ab024_0 599 KB conda-forge libssh2-1.10.0 | h04015c4_3 279 KB libzip-1.9.2 | h6db710c_1 117 KB conda-forge numpy-1.26.4 | py311h91b6869_0 12 KB numpy-base-1.26.4 | py311hb3ec012_0 7.8 MB pyopenssl-25.1.0 | pyhd8ed1ab_0 120 KB conda-forge python-3.11.0 |he7542f4_1_cpython 14.7 MB conda-forge xarray-2025.4.0 | py311hecd8cb5_0 2.9 MB

------------------------------------------------------------ Total: 34.2 MB The following NEW packages will be INSTALLED: curl conda-forge/osx-64::curl-7.88.1-h6df9250_0 The following packages will be SUPERSEDED by a higher-priority channel: cryptography conda-forge::cryptography-46.0.5-py31~ --> pkgs/main::cryptography-45.0.5-py311hc0e11ad_0 krb5 conda-forge::krb5-1.22.2-h207b36a_0 --> pkgs/main::krb5-1.20.1-h428f121_1 libssh2 conda-forge::libssh2-1.11.1-hed3591d_0 --> pkgs/main::libssh2-1.10.0-h04015c4_3 mhkit conda-forge/osx-64::mhkit-1.0.1-py311~ --> conda-forge/noarch::mhkit-0.8.0-pyhd8ed1ab_0 netcdf4 conda-forge::netcdf4-1.7.2-nompi_py31~ --> pkgs/main::netcdf4-1.7.2-py311hac2bb38_1 openssl conda-forge::openssl-3.6.1-hb6871ef_1 --> pkgs/main::openssl-3.0.17-hee2dfae_0 xarray conda-forge/noarch::xarray-2026.2.0-p~ --> pkgs/main/osx-64::xarray-2025.4.0-py311hecd8cb5_0 The following packages will be DOWNGRADED: h5py 3.12.1-nompi_py311h1c45a99_103 --> 3.8.0-nompi_py311h777de7a_100 h5pyd 0.23.0-pyhd8ed1ab_0 --> 0.22.0-pyhd8ed1ab_0 hdf5 1.14.4-nompi_h1607680_105 --> 1.12.2-nompi_h48135f9_101 libcurl 8.18.0-h9a2545f_1 --> 7.88.1-h6df9250_0 libnetcdf 4.9.2-nompi_hd7a758f_116 --> 4.8.1-nompi_hc61b76e_106 libnghttp2 1.67.0-h3338091_0 --> 1.52.0-he2ab024_0 libzip 1.11.2-h31df5bb_0 --> 1.9.2-h6db710c_1 numpy 2.0.1-py311h13f252e_1 --> 1.26.4-py311h91b6869_0 numpy-base 2.0.1-py311ha745260_1 --> 1.26.4-py311hb3ec012_0 pyopenssl 25.3.0-pyhd8ed1ab_0 --> 25.1.0-pyhd8ed1ab_0 python 3.11.11-h9ccd52b_2_cpython --> 3.11.0-he7542f4_1_cpython Proceed ([y]/n)? y Downloading and Extracting Packages: Preparing transaction: done Verifying transaction: done Executing transaction: done (mhkit) Mac-mini:~ dwi$ In Matlab:

> pyenv(Version="/opt/anaconda3/envs/mhkit/bin/python")

ans = PythonEnvironment with properties: Version: "3.11" Executable: "/opt/anaconda3/envs/mhkit/bin/python" Library: "/opt/anaconda3/envs/mhkit/lib/libpython3.11.dylib" Home: "/opt/anaconda3/envs/mhkit" Status: NotLoaded ExecutionMode: OutOfProcess

> l = py.list({'a', 'b', 'c'})

l = Python list with values: ['a', 'b', 'c'] Use string, double or cell function to convert to a MATLAB array.

> [x, y] = circular(30)

Error using motion><module> (line 5) Python Error: ImportError: cannot import name 'cumtrapz' from 'scipy.integrate' (/opt/anaconda3/envs/mhkit/lib/python3.11/site-packages/scipy/integrate/__init__.py) Error in api><module> (line 4) Error in __init__><module> (line 1) Error in __init__><module> (line 10) Error in performance><module> (line 5) Error in __init__><module> (line 4) Error in __init__><module> (line 4) Error in <frozen importlib>_call_with_frames_removed (line 241) Error in <frozen importlib>exec_module (line 940) Error in <frozen importlib>_load_unlocked (line 690) Error in <frozen importlib>_find_and_load_unlocked (line 1149) Error in <frozen importlib>_find_and_load (line 1178) Error in <frozen importlib>_gcd_import (line 1206) Error in __init__>import_module (line 126)

…

> On Wed, Mar 18, 2026 at 6:56 PM Andrew Simms ***@***.***> wrote: *simmsa* left a comment (MHKiT-Software/MHKiT-MATLAB#197) <#197 (comment)> I installed Matlab 2024b. It seems a small progress: l = py.list({'a', 'b', 'c'}) l = Python list with values: ['a', 'b', 'c'] Use string, double or cell function to convert to a MATLAB array. [x, y] = circular(30) Python Error: ImportError: dlopen(/opt/anaconda3/envs/mhkit/lib/python3.11/site-packages/netCDF4/_ netCDF4.cpython-311-darwin.so, 0x000A): Symbol not found: _SSL_get0_group_name Referenced from: <9C5CC915-156B-36DB-8C78-45A97DF0BDC8> /opt/anaconda3/envs/mhkit/lib/libcurl.4.dylib Expected in: <4447AD75-60CC-3855-8373-857D31DCFC1E> /Applications/MATLAB_R2024b.app/bin/maci64/libssl.3.dylib Error in circular (line 24) result=py.mhkit.river.performance.circular(diameter); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @DwiNY2026 <https://github.com/DwiNY2026>, this is good progress. It looks like Python is working now. The above is a MacOS specific error that I have dealt with before. It is a bit tricky as everyones computer is a bit different here. In the mhkit conda environment can you try this step: conda install openssl=="3.0.*" And restart matlab and try that same command and paste in the result if it does not work? These errors are specific Anaconda and MATLAB incompatibilities, that are not documented anywhere and require a bit of trial and error to actually fix. — Reply to this email directly, view it on GitHub <#197 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/CAGO7PBZGABQQDYESOHFAJ34RMSTJAVCNFSM6AAAAACWW5HC26VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHM2DAOBWGEYDINJYGM> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[simmsa]

@DwiNY2026, the above is good progress. I think there is one more scipy step that will help get this working (This is typically the last issue like this in my own experience and MHKiT-MATLAB should work nominally after this step):

Please try this inside of the mhkit conda environment:

pip uninstall -y scipy

pip install scipy==1.12.0

And try restarting MATLAB.