{
  "status": "shipping",
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-22",
  "slug": "hdf5-dimension-scale",
  "term": "HDF5 dimension scale",
  "aliases": [
    "H5DS dimension scale"
  ],
  "definition": "An HDF5 dimension scale is a dataset associated with an array dimension to supply application-defined coordinates or labels.",
  "note": "Identity: a scale's name is separate from its dataset path and need not be unique. h5py name lookup returns the first matching attached scale, while the HDF5 storage profile does not define scale-list order. Do not treat insertion order as a portable selection rule. [h5py-dims] [h5ds-spec]\n\nConsistency: an axis label does not attach a scale. Coordinate interpretation and compatible extents are application responsibilities; several scales or unequal extents may be intentional. [h5ds-spec]\n\nObserved consequence: in two synthetic HDF5 builds, selecting between duplicate time-scale names changed an endpoint rate from 10 to 1 count/s with identical value-array bytes. Thirteen of fourteen cases were numerically readable, but only two met the experiment's single-time-axis policy. These are configuration outcomes, not reliability frequencies. [hesela-dimensions]",
  "related": [
    "hdf5",
    "hdf5-swmr"
  ],
  "advantages": [],
  "limitations": [],
  "citations": [
    {
      "id": "h5ds-spec",
      "title": "The HDF Group: HDF5 High Level Dimension Scales, storage profile and limitations",
      "url": "https://support.hdfgroup.org/documentation/hdf5/latest/_h5_d_s__u_g.html",
      "accessed": "2026-10-22"
    },
    {
      "id": "h5py-dims",
      "title": "h5py: Dimension Scales",
      "url": "https://docs.h5py.org/en/stable/high/dims.html",
      "accessed": "2026-10-22"
    },
    {
      "id": "hesela-dimensions",
      "title": "Hesela: HDF5 coordinate selection, two-build controlled observations",
      "url": "https://hesela.com/analyses/hdf5-swmr-application-consistency/#dimension-scales",
      "accessed": "2026-10-22"
    }
  ],
  "provenance": [
    "Hesela's synthetic files were observed with h5py 3.10.0/HDF5 1.14.2 and h5py 3.15.0/HDF5 1.14.6. Writers closed before fresh readers opened; no live acquisition, H5MD consumer or power-loss behavior was tested."
  ]
}