The phrase "a function of the index of" is correct and usable in written English.
It can be used in contexts involving mathematics, statistics, or programming, where you are describing a relationship or dependency between variables.
Example: "The output of the algorithm is a function of the index of the input data set."
Alternatives: "dependent on the index of" or "related to the index of".
Fig. 7. Left plot shows differences as defined in (1) between IGRF-2010 candidate models and the arithmetic mean Model M as a function of the index of the spherical harmonic coefficient (running from etc indexed 1, 2, 3, 4, 5, etc).
Fig. 2. Left plot shows differences as defined in (1) between DGRF-2005 candidate models and their mean model M as a function of the index of the spherical harmonic coefficient (running from etc indexed 1, 2, 3, 4, 5, etc).
Right plot shows Huber robust weighting factor i w α (1.0 full weight, 0.0 zero weight) also as a function of the index of the spherical harmonic coefficient.
The right hand plot in Fig. 7 displays the Huber weights as a function of the index of the spherical harmonic coefficient.
Fig. 3 a Spectral reflectance for an optimum design that uses AZO as the buffer layer as a function of the index of refraction of the medium under test.
Right plot shows Huber robust weighting factors i w α for the candidate models for IGRF-2010 (1.0 full weight, 0.0 zero weight) also as a function of the index of the spherical harmonic coefficient.
We show the calculated critical angle as a function of the refractive index of the scintillator in Fig. 1(B) for air (refractive index: 1) and a typical example of glass (refractive index: 1.5).
Supplementary Fig. 11b plots the visuomotor index as a function of the depth for this session.
The survival was analysed as a function of prognostic indices.
This index can be expressed well as a function of other solar indices.
Resonant peaks of plasmonic gold nanoparticles were tracked as a function of their surrounding refractive index.
