{
  "status": "shipping",
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-17",
  "slug": "hdf5-fill-value",
  "term": "HDF5 fill value",
  "aliases": [],
  "definition": "An HDF5 fill value is the configured or default value supplied for dataset elements that lack stored or available mapped data.",
  "note": "Creation property: H5Pset_fill_value defines the value using a datatype; the default is zero interpreted for the dataset datatype. A suitable application may reserve an otherwise invalid value to make missing data conspicuous. [h5-properties]\n\nVirtual data: a missing source can produce fill values through a VDS read. Such an output value is not automatically a measurement, a validity mask or proof of a storage fault. [h5-vds]\n\nInterpretation: an explicit sentinel helps only if the application treats it as missing and excludes it from valid data. It cannot identify the intended source when another valid dataset is resolved in its place. [hesela-vds]",
  "related": [
    "hdf5",
    "hdf5-virtual-dataset"
  ],
  "citations": [
    {
      "id": "h5-vds",
      "title": "The HDF Group: Introduction to the Virtual Dataset",
      "url": "https://support.hdfgroup.org/documentation/hdf5/latest/_v_d_s_t_n.html",
      "accessed": "2026-10-17"
    },
    {
      "id": "h5-properties",
      "title": "The HDF Group: H5Pset_virtual source-file resolution and H5Pset_fill_value",
      "url": "https://support.hdfgroup.org/documentation/hdf5/latest/group___d_c_p_l.html",
      "accessed": "2026-10-17"
    },
    {
      "id": "hesela-vds",
      "title": "Hesela: HDF5 virtual dataset dependency observations",
      "url": "https://hesela.dev/datasets/hdf5-vds-dependencies/",
      "accessed": "2026-10-17"
    }
  ],
  "advantages": [],
  "limitations": []
}