MFEM - Finite Element Discretization Library

Getting Started

15 minutes basic

Lesson Objectives

Setup a browser-based MFEM development environment.
Run a simple MFEM code to test the environment.

Note

If you are part of the HPC software tutorial series, use the URLs sent by the Slackbot when it starts your development container. For example, the Slackbot message includes URLs for VS Code and GLVis like https://SESSION.mfem.hpcic.training?folder=/home/euler/mfem and https://SESSION.mfem.hpcic.training/glvis/live/?socket=/glvis-ws.

If you are running a Docker container locally, follow the local URLs in the Local Docker Container page.

Set up VS Code

Open the VS Code URL in a new browser window.
You should see the Visual Studio Code (VS Code) interface.
Click on Mark Done to continue.
If the VS Code URL includes ?folder=/home/euler/mfem, the MFEM directory opens automatically and you can skip the next step.

(If needed) Click on open a folder (under Recent), then select mfem, then click OK.
In the left pane, open examples and select ex1.cpp.
Open a new terminal by clicking on in the upper left corner, then Terminal, and then New Terminal.
Alternatively you can open a new terminal by pressing Ctrl + Shift + `.
You should now see the MFEM source tree and a terminal in the ~/mfem directory.

Note

The browser window contains a fully functioning copy of Visual Studio Code. You can customize it further, and adjust it similarly to the desktop version.

Set up GLVis

In this tutorial we use GLVis for finite element visualization based on MFEM.

Open the GLVis URL in a new browser window.
When you move the mouse to the top of the window you should see the GLVis interface:

If the GLVis URL includes ?socket=/glvis-ws, it is already connected and you can skip the next step.
(If needed) Click the Connect to socket icon in the upper left corner, then enter the current host name followed by /glvis-ws in the Host field, for example SESSION.mfem.hpcic.training/glvis-ws or localhost:3000/glvis-ws, and click CONNECT. When the button switches to DISCONNECT, click outside of the Connect to socket dialog to close it.
Your environment should now look like:

Simple test

To test your environment, run ex1, which together with the MFEM library itself, comes pre-build in the AWS image.
In the VS Code terminal, type
```
cd examples
./ex1
```
You should see 111 iterations printed in the terminal and the image in the GLVis window should change:

To test the visualization, click in the GLVis window, and make sure you can rotate the plot with the Left mouse button and zoom in/out with the Right mouse button.

Questions?

Ask for help in the tutorial Slack channel.

Next Steps

Go to the Finite Element Basics page.

Back to the MFEM tutorial page