14. Entity Types¶
The entity_type tells the reader what is being described in a file and, in
concert with the data_kind, helps connect the right file to
the right reader API. There are currently four controlled values:
entity_type |
Description |
|---|---|
spectrum |
Mass spectra — entities occurring at a single point in time (or as close to that as framed or cycled acquisition allows), with a mass-related coordinate such as m/z or neutral mass. |
chromatogram |
Measurements over time — chromatograms and, for now, diagnostic traces (see below). |
wavelength_spectrum |
Like spectrum, but the coordinate is an electromagnetic wavelength. Analyzers measuring wavelength are far more heterogeneous than mass analyzers. Time series over wavelength may instead be stored as chromatogram entries. |
provenance |
A cryptographic signature of components of the archive used for certifying that the content as written was attested to by an instrument known to its owner or vendor |
proprietary |
implementation-defined |
other |
None of the above — something not yet covered by this living specification. |
Any value outside this list is treated as other, but implementations MUST preserve
the value provided rather than discarding the entity type label and recording an
undifferentiated "other". This permits forward compatibility as new entity types are
added without updating existing code.
14.1 Adding a new entity type¶
When a genuinely new kind of measured entity appears that does not fit
spectrum, chromatogram, or wavelength spectrum, a new entity type may be
introduced. Prefer a short, lower-case name, define its primary coordinate axis
and the data kinds it supports, and describe its relationship to
existing entity types.
Open item — naming
Should the chromatogram entity type be renamed to something broader such as
traces, now that diagnostic traces are moving to their own namespace? Left
open.