Foeppl Fingerprint¶

This sample generates paper-oriented experiments for the LIBXS Foeppl fingerprint API. It focuses on the fingerprint itself, leaving Rosetta as the higher-level algebra/type-discovery showcase.

What It Produces¶

Set FPRINT_OUTDIR to collect CSV artifacts:

mkdir -p results/fprint
FPRINT_OUTDIR=results/fprint ./fprint.x

The sample writes:

File	Purpose
`convergence.csv`	Same functions sampled at increasing resolution and compared to a high-resolution reference.
`sensitivity.csv`	Perturbations with matched element RMS but different structural character.
`geometry.csv`	Foeppl boundary area, centroid, moments, and shape fingerprints.
`hierarchy.csv`	2-D smooth, creased, diagonal-creased, and noisy fields in hierarchical and per-axis modes.
`compression.csv`	Newton truncation order versus reconstruction error.
`collision.csv`	Pseudometric collision test: pairs with shared L2 norms but different signed means.
`timing.csv`	Wall-clock cost per element at various input sizes.
`convergence_rate.csv`	Log-log convergence rate (slope and R-squared) for smooth functions.

Build¶

cd samples/fprint
make GNU=1

Use From The Paper¶

The Foeppl paper driver papers/foeppl/run.sh builds this sample when needed and stores artifacts under papers/foeppl/results/fprint by default.