The phrase "a fixed feature" is correct and usable in written English.
It can be used to describe something that is permanent or unchanging in a particular context.
Example: "The old clock on the wall has become a fixed feature of the room, adding character and charm to the decor."
Alternatives: "an established element" or "a permanent aspect".
Traditionally, the comparison of classification systems is accomplished for a fixed feature set.
This charge is a fixed feature of all electrons; each has the same amount of it as any other.
There are many models of human cognition that, basically, assume a fixed feature set, but if you just get some of the feature.
This high vote for a party which has never looked more dysfunctional is beginning to look like a fixed feature of local politics.
Midrange photographs are designed to include both an item of evidence and a fixed feature of the scene in the same photograph.
For as long as shyness has existed, its sufferers have wished it away, but in 18th- and 19th-century Britain, the condition was, the book suggests, accepted as a fixed feature of some people's personality.
Furthermore, any fixed feature of probe performance such as GC content that affect intensity cannot explain a correlation, which depends on coordinated variation in intensity.
The compositional vector amino acid and dipeptide for a sequence has fixed feature input (20 and 400 respectively) irrespective of length of the peptide.
Traditional fixed price, fixed feature deliverable-focused task orders kill agile projects.
The feature selection method enlarged the fixed feature set.
It also has the ability to build photo collages in-app, a "face fix" feature that includes functions to help you quickly make self-portraits more flattering by slimming your jawline or widening your eyes, and filters that give your photos a pop art look (in addition to the usual aged film or distressed-look overlays that other photo editing apps have).
