Add the cymbal tier
1 changed file+8−4
README.mdmodified+8−4View file
@@ -8,6 +8,7 @@ The results are published as static sites, one per tier:
88 | --- | --- | --- |
99 | 0, string | [challenges/string](https://vault1.magland.org/challenges/string) | [results](https://vault1.magland.org/challenges/string/site/) |
1010 | 1, plate | [challenges/plate](https://vault1.magland.org/challenges/plate) | [results](https://vault1.magland.org/challenges/plate/site/) |
11+| 2, cymbal | [challenges/cymbal](https://vault1.magland.org/challenges/cymbal) | [results](https://vault1.magland.org/challenges/cymbal/site/) |
1112
1213 ## Background
1314
@@ -21,8 +22,8 @@ There is no externally supplied ground truth. The reference for each challenge i
2122
2223 Each tier is a pair of repositories, plus shared tooling.
2324
24-- **A challenge repository** (`challenges/string`, `challenges/plate`) holds the specifications: one directory per challenge with a `README.md`, which is the authoritative definition, and a `challenge.json`, which repeats the parameters, output format, error measures, and the grid of the optional field export in machine-readable form. It also holds a registry of solution repositories and the workflow that builds the comparison site.
25-- **Solution repositories** (`challenges/string-solutions`, `challenges/plate-solutions`, and any others that are registered) hold submissions: a JSON file per submission with metadata and one or more solutions, the output wav files, optional field exports for visualization, and whatever else the authors want, such as solver code or their own visualization site. A solution repository runs only the validator; it makes no comparisons of its own.
25+- **A challenge repository** (`challenges/string`, `challenges/plate`, `challenges/cymbal`) holds the specifications: one directory per challenge with a `README.md`, which is the authoritative definition, and a `challenge.json`, which repeats the parameters, output format, error measures, and the grid of the optional field export in machine-readable form. It also holds a registry of solution repositories and the workflow that builds the comparison site.
26+- **Solution repositories** (`challenges/string-solutions`, `challenges/plate-solutions`, `challenges/cymbal-solutions`, and any others that are registered) hold submissions: a JSON file per submission with metadata and one or more solutions, the output wav files, optional field exports for visualization, and whatever else the authors want, such as solver code or their own visualization site. A solution repository runs only the validator; it makes no comparisons of its own.
2627 - **The tools** (`challenges/challenge-tools`) are a small Python package with the submission schema, the validator, the error measures, the reference-selection rule, and the generator of the comparison site. Every challenge repository installs it in its workflow.
2728
2829 The comparison workflow of a challenge repository clones every registered solution repository, reads the committed output files, computes every pairwise error, chooses the reference, and deploys the site. It runs on every push to the challenge repository or when dispatched by hand. Nothing in the vault triggers across repositories, so a push to a solution repository is picked up at the next run of the challenge repository's workflow. All solvers run on the submitters' own machines; the workflow runner only scores committed files.
@@ -50,8 +51,9 @@ The rule is only as good as the assertions. A sequence that is not in fact monot
5051 | [string-pluck-v1](https://vault1.magland.org/challenges/string/blob/main/challenges/string-pluck-v1/README.md) | Damped string with fixed ends, released from its static equilibrium under a finger load | 2 s of pickup velocity |
5152 | [plate-strike-v1](https://vault1.magland.org/challenges/plate/blob/main/challenges/plate-strike-v1/README.md) | Free 12 in aluminum plate, linear 3D elastodynamics with Kelvin-Voigt damping, struck by a short force pulse | 3 s of radiated pressure by the Rayleigh integral |
5253 | [plate-strike-nl-v1](https://vault1.magland.org/challenges/plate/blob/main/challenges/plate-strike-nl-v1/README.md) | The same plate as a Saint Venant-Kirchhoff solid (geometrically nonlinear), struck by a soft mallet | 3 s of radiated pressure |
54+| [cymbal-flat-disk-v1](https://vault1.magland.org/challenges/cymbal/blob/main/challenges/cymbal-flat-disk-v1/README.md) | Flat, free 16 in bronze disk of uniform thickness, Saint Venant-Kirchhoff, struck near the rim by a stick-like pulse | 6 s of radiated pressure |
5355
54-The string challenge is a hello world: its modal series solution is essentially exact, so it exercises the submission and scoring pipeline and gives a check on the reference rule. The plate challenges define three-dimensional models, so the thin-plate solutions submitted so far (Kirchhoff-Love finite elements for the linear plate, a modal von Kármán method for the nonlinear one) are approximations whose error relative to a future converged three-dimensional solution includes the modeling error of plate theory. Until such a solution arrives, the reference is the best thin-plate solution and the errors measure only differences within plate theory; the results pages say so.
56+The string challenge is a hello world: its modal series solution is essentially exact, so it exercises the submission and scoring pipeline and gives a check on the reference rule. The plate challenges define three-dimensional models, so the thin-plate solutions submitted so far (Kirchhoff-Love finite elements for the linear plate, a modal von Kármán method for the nonlinear one) are approximations whose error relative to a future converged three-dimensional solution includes the modeling error of plate theory. Until such a solution arrives, the reference is the best thin-plate solution and the errors measure only differences within plate theory; the results pages say so. The cymbal tier starts from a flat disk and will add the features of a real cymbal one at a time (bell, bow, hammering, varying thickness), each as a new challenge, so that the effect of each on the sound and on the cost of computing it can be seen in isolation; its first solutions are von Kármán modal solutions on Cartesian grids that approximate the disk by a staircase.
5557
5658 ## Conventions
5759
@@ -68,7 +70,7 @@ The string challenge is a hello world: its modal series solution is essentially
6870
6971 ## Roadmap
7072
71-The tiers sketched in the research plan, for a cymbal as the running example, are: a flat plate struck at a point (tier 1, done in linear and nonlinear form); a curved, cymbal-shaped shell (tier 2); large-amplitude strikes with geometric nonlinearity on that shell (tier 3); and sound radiated into the surrounding air by a coupled structure and acoustic simulation (tier 4), replacing the Rayleigh integral used so far. Alongside the tiers we intend to pursue simulations of complete instruments, starting with a cymbal on a stand, which are harder to benchmark but show which effects matter most for the sound and so guide which challenges to add. Open questions include which errors are audible, since a cheaper model can have a large waveform error yet sound identical, and the collection is a natural place to host listening tests once there are enough solutions to compare.
73+The tiers sketched in the research plan, for a cymbal as the running example, are: a flat plate struck at a point (tier 1, done in linear and nonlinear form); a curved, cymbal-shaped shell (tier 2, begun with the flat disk); large-amplitude strikes with geometric nonlinearity on that shell (tier 3); and sound radiated into the surrounding air by a coupled structure and acoustic simulation (tier 4), replacing the Rayleigh integral used so far. Alongside the tiers we intend to pursue simulations of complete instruments, starting with a cymbal on a stand, which are harder to benchmark but show which effects matter most for the sound and so guide which challenges to add. Open questions include which errors are audible, since a cheaper model can have a large waveform error yet sound identical, and the collection is a natural place to host listening tests once there are enough solutions to compare.
7274
7375 ## Repositories in this collection
7476
@@ -80,3 +82,5 @@ The tiers sketched in the research plan, for a cymbal as the running example, ar
8082 | [string-solutions](https://vault1.magland.org/challenges/string-solutions) | solutions to the string challenges, with a 2D field viewer |
8183 | [plate](https://vault1.magland.org/challenges/plate) | tier 1 specifications, registry, comparison site |
8284 | [plate-solutions](https://vault1.magland.org/challenges/plate-solutions) | solutions to the plate challenges, with a 3D field viewer |
85+| [cymbal](https://vault1.magland.org/challenges/cymbal) | tier 2 specifications, registry, comparison site |
86+| [cymbal-solutions](https://vault1.magland.org/challenges/cymbal-solutions) | solutions to the cymbal challenges, with a 3D field viewer |