ayz2/emmi_wing_processed

Emmi-Wing (processed)

This is a processed, downsampled version of Emmi Wing, not the original dataset. Fields were converted to a common frame and non-dimensionalized, rows were randomly subsampled and some variables were dropped. For the original data, see the original paper

The original size was 4.6 TB, therefore there we downsampled the volume field by 5x to obtain a size of 0.83 TB.

Layout

collated/                 surface
  manifest.json           [{stem, n_points, n_points_source, ...}]
  splits/{train,val}.json
  norm_stats*.npz         per-column normalization statistics
  samples/<stem>.npy   (packed in shards/*.tar, see below)
volume_collated/          volume
  manifest.json
  norm_stats_volume*.npz
  samples/<stem>.npy   (packed in shards/*.tar, see below)
RELEASE.json              downsampling factors, columns and row totals

This dataset has ~29k samples per tree, so the per-sample files are packed into ~5 GB uncompressed tar shards to stay within Hub file-count limits. The member paths are relative to the dataset root, so this reproduces the per-sample layout above:

cd <download dir>
for f in collated/shards/*.tar volume_collated/shards/*.tar; do tar -xf "$f"; done

<tree>/shards/index.json maps each stem to its shard. A single sample can be pulled with tar -xf <shard> <tree>/samples/<stem>.npy.

Columns

Surface (collated, 7 columns):

col	name	meaning
0	x	position
1	y	position
2	z	position
3	cp	pressure coefficient
4	cf_x	skin-friction coefficient
5	cf_y	skin-friction coefficient
6	cf_z	skin-friction coefficient

Dropped from this release: rho_tilde.

Volume (volume_collated, 7 columns):

col	name	meaning
0	x	position
1	y	position
2	z	position
3	ux	velocity
4	uy	velocity
5	uz	velocity
6	cp	pressure coefficient

Dropped from this release: rho_tilde, wx, wy, wz.

Splits

The volume tree uses the surface splits (keyed by stem).

• train: 26,648 samples
• val: 2,961 samples

Either use norm_stats_centered.npz, or norm_stats_thinned.npz. The centered stats are computed on the simulation mesh (i.e., native discretization), while the thinned stats are computed after (roughly) uniform sampling.