Installing and Running MFEM using Spack

This guide documents how to install and run the MFEM examples using Spack.

Tested on MacOS (Apple Silicon) with MPI.

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1. Install Spack

Clone Spack:

git clone https://github.com/spack/spack.git
cd spack

Activate Spack:

source share/spack/setup-env.sh

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2. Detect Compilers

Let Spack detect available compilers.

spack compiler find

Example output:

gcc@15.2.0
apple-clang@17.0.0

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3. Create a Spack Environment

Create an environment for FEM development.

spack env create fem-learning
spack env activate fem-learning

Verify:

spack env status

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4. Install Required Packages

Install MFEM and dependencies.

spack install mfem
spack install glvis

These packages will also install dependencies such as:

• HYPRE
• Open MPI
• METIS
• zlib

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5. Load the Libraries

Load required packages into the shell.

spack load mfem
spack load hypre
spack load openmpi
spack load metis
spack load zlib-ng

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6. Define Library Paths

Set paths to installed libraries.

export MFEM_DIR=$(spack location -i mfem)
export HYPRE_DIR=$(spack location -i hypre)
export METIS_DIR=$(spack location -i metis)
export ZLIB_DIR=$(spack location -i zlib-ng)

Verify:

echo $MFEM_DIR

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7. Compile an MFEM Example

Compile example ex18 (DG advection solver).

mpicxx ex18.cpp \
-I$MFEM_DIR/include \
-I$HYPRE_DIR/include \
-I$METIS_DIR/include \
-L$MFEM_DIR/lib \
-L$HYPRE_DIR/lib \
-L$METIS_DIR/lib \
-L$ZLIB_DIR/lib \
-lmfem -lHYPRE -lmetis -lz \
-o ex18

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8. Run the Example

Run in serial:

./ex18

Run with MPI:

mpirun -n 4 ./ex18

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9. Visualization with GLVis

Start GLVis in a separate terminal:

glvis

Then run the simulation to visualize results in real time.

GLVis is a visualization tool designed specifically for MFEM simulations.

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10. What the Example Solves

Example 18 solves the advection equation using a discontinuous Galerkin method.

[ \frac{\partial u}{\partial t} + \mathbf{v} \cdot \nabla u = 0 ]

This equation models transport phenomena such as:

• temperature transport
• species concentration
• vorticity transport

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11. Next Steps

After successfully running MFEM examples, explore:

• Poisson solver (ex1)
• diffusion solver (ex9)
• advection solver (ex18)
• Navier–Stokes miniapps

These cover the main PDE classes used in CFD.

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If you'd like, I can also give you a clean “MFEM learning roadmap” Gist (which examples to run and in what order) so you don't get lost in the 20+ examples.