1.2. Install on MacOS

1.2.1. Install Python 3.9

SimCenter tools require an x86-based Python 3.9. If your current Python version is incompatible, follow these steps to install the required version from Python.org.

  1. To check your Python version compatibility, issue the following in a terminal window.

    import platform

    Ensure the output indicates Python 3.9 and machine=’x86_64’, as shown in the screenshot below. If not, proceed to install Python 3.9 x86.


    Fig. Python: Kernel Version

  2. Visit Python.org and download the macOS 64-bit Intel-only installer for Python 3.9.


    Fig. Python: python.org MacOS Download Page

  3. Run the installer. Upon completion, a folder with several files will open, as shown in the figure below. Execute Update Shell Profile.command.sh and Install CertificateCommand.sh by double-clicking each.


    Fig. Python: Folder Displayed at Conclusion of Install

  4. Install additional packages via the nheri_simcenter package by starting a Terminal window and type the following command:

    pip3 install nheri_simcenter --upgrade
    python3 -m pip3 install --upgrade nheri_simcenter


    Use of pip versus pip3, and python versus python3 or python3.9 may vary depending on your system configuration. If the above commands fail, try using pip and python instead.

    Make sure you see a message that confirms the successful installation of the nheri-simcenter package before proceeding to the next step.


  1. If you forget to invoke the UpdateShellProfile.command.sh script at the end of the install, you can always execute the correct shell file later to update the PATH variable to point to the Python application. On Linux systems, the shell is the program that takes commands from the keyboard that you enter in the terminal window and passes them to the operating system to perform by invoking applications and passing data between applications. In the good old days, it was the only interface available to the user, i.e., there was no such thing as Finder! There are a number of shell programs that can be installed and made available to you. The most popular is the bash shell, and the up-and-coming one is the Z shell. Power MacOS users will write shell scripts to do many useful things. By default, the applications that the shell program will invoke are limited to applications in a few specific directories that are defined in the user’s PATH. Users can modify this path by editing files that the shell program will read from every time the program is started. When the frontend application is running the computations it is actually running a backend application using the shell program. As a consequence the shell program must be made aware of the locations of some of the external applications that you have installed as OpenSees and Dakota do not provide installers that automatically do this when they are installed. Other applications, like Tcl provide scripts that you invoke to do it. In short, you have to edit the file appropriate to the shell you are using.

    To find which shell program you are using when you issue commands inside the terminal window, type the following:

    env | grep SHELL

    If the result is /bin/bash you will need to edit the .bashrc file or the bash_profile file. If the result is /bin/zsh you will need to edit the .zshrc or .zprofile. Typically, the .bash_profile or the .zprofile file is the one to edit as by design these will invoke the .bashrc or .zshrc file. If in doubt, look for these files in your home directory and see which of these other installers have modified.

  2. Python 3.10 from python.org will also work, though there is no x86 installer. The reason we do not recommend its usage is that there are additional settings that need to be modified in the application under the Preferences tab as that python package has a different mechanism for invoking the x86 version, specifically python3-intel64.

1.2.3. Install OpenFOAM for macOS

This version of the WE-UQ app uses OpenFOAM for pre-processing the CFD model. At the backend, the mesh generation and visualization in the GUI utilize OpenFOAM-10 built-in meshing tools.


The packaged distribution of OpenFOAM is only available for Linux systems. To install OpenFOAM on macOS, the user needs to use Docker for Mac. Docker will provide a virtual environment for running Linux applications on macOS.

To install OpenFOAM-10 on macOS, follow the instructions in OpenFOAM for macOS .

1.2.5. Download the Application

To download the WE-UQ app, navigate to the WE-UQ Download page which should resemble Fig. The download page contains a list of downloadable files and directories.


Fig. WE-UQ download page.

Click on the file with a name ending with Mac_Download.dmg to download the WE-UQ app. In the pop-up window, click on the Download button in the bottom right corner. After the download is completed, open the dmg file and copy the WE-UQ app to a location in your filesystem.


We suggest copying the application to your Desktop. After copying the application, you can move the dmg file to the trash or eject it.

1.2.6. Test the Installation

Once the installation procedure has been completed, it is a good practice to run some basic checks. Navigate to the location where you placed the application and open it by running the WE-UQ.exe executable.


SimCenter apps are code-signed and notarized, but because they are not downloaded from the operating system’s app store, they may not be recognized as safe applications. Depending on your security settings, when you start a SimCenter app for the first time, your operating system may show a dialog box indicating it is unsafe. If this dialog appears, choose the cancel button. Try to start the app again, this time by right-clicking on it and selecting open.

If the app still fails to open. You need to go to System Settings->Privacy and Security. Under the Security section, you need to at least temporarily select the option to allow applications downloaded from the App Store and Identified Developers. With this checked try again. If it fails again, go back to System Settings->Privacy and Security. Just below the section you just checked, there should be some text about why the app was stopped and an option to Open Anyway, as shown in the figure below. Click on the button and the app should start.


Once the application starts, verify the setup by running an example problem 9 Story Building: Sampling Analysis, see Fig.


Fig. WE-UQ application on startup.


When the WE-UQ app is running, open the app/preferences or File/Preferences and make sure that python3 appears under External Applications:Python, as shown in the figure below. If you used older versions of SimCenter tools this was not the default. The exact location of Python3 that you installed can be found by opening the terminal application and executing the which python3 command. Enter the path shown as a response in the Preferences panel under Python and then press the Save button.


Fig. Set Python Preferences.