Matplotlib Testing for the RISE SW Stack

A successful execution of the following test will verify the installation and headless rendering capabilities of Matplotlib on the new RISE software stack.

Two Python script is provided for testing:

• matplotlib_sanity.py - tests Matplotlib's ability to operate on headless HPC compute nodes. It forces the non-interactive Agg backend, draws a figure containing both line and scatter plots, and verifies that the resulting image successfully exports to disk without requiring an X11 window display.

Note: The official Matplotlib pytest suite is not used here, as the massive baseline image directory required for pixel-comparison testing is intentionally stripped from HPC installations to save disk space.

Step 1: Environment Setup

We must first set up the environment by loading the appropriate modules and creating a virtual environment.

Note: As of this writing, the py-matplotlib/3.10.7 module is missing several core runtime dependencies (like packaging and kiwisolver). We use the virtual environment to temporarily patch these missing dependencies so the library can run.

1. Load the required modules:

# Clear existing modules
module purge

# Load the RISE software stack, NumPy, and Matplotlib
module use /storage/icds/sw8/modulefiles_rc2026/linux-rhel8-x86_64/Core
module load gcc
module load py-numpy
module load py-matplotlib/3.10.7

2. Create and activate a virtual environment:

python -m venv --system-site-packages ./mpl_test_env
source ./mpl_test_env/bin/activate

3. Install missing runtime dependencies:

pip install packaging contourpy cycler fonttools kiwisolver pillow pyparsing python-dateutil

Step 2: Run the Core Sanity Check (matplotlib_sanity.py)

Because compute nodes do not have graphical displays, this script forces Matplotlib to use the Agg backend. It generates a figure containing a line plot and a scatter plot, and exports it directly to disk as a PNG file.

Run the test script:

python matplotlib_sanity.py 

Expected Output:

--- Matplotlib Sanity Check ---
Version: 3.10.7
Backend: Agg

1. Testing basic line plot and scatter plot...
2. Testing file export (PNG)...
   -> Success! Plot saved to matplotlib_test_output.png.

 Matplotlib 3.10.7 is installed and functioning correctly!

Step 3: Cleanup

Once testing is complete, you can deactivate and remove the virtual environment, and delete the generated test image:

deactivate
rm -rf ~/mpl_test_env
rm matplotlib_test_output.png