Define separate methods for the three public coefficient functions

This specifies things more clearly, although now the names are kinda
long, but that's not really a big deal as these functions aren't meant
to be used frequently and this avoids confusion; if they are to be used
they will probably be used in an automated fashion.

What this also does is instead of just creating aliases these distinct
functions now directly access the desired quantities.

README.md

@@ -196,6 +196,6 @@ For the `standardize` subset method the tuples in `orders` must be of the form `
 
 * If you're interested in only the full vector of Zernike expansion coefficients obtained through the least squares fit and want to avoid computing extra values and plotting the results you can call:
 ```julia
-Zernike.reconstruct(ρ, θ, OPD, n_max)[1]
+Zernike.wavefront_coefficients(ρ, θ, OPD, n_max)
 ```
-Similarly you can do this for the radial polynomial coefficients and the NA transformed wavefront error expansion coefficients by importing the functions `coefficients` and `transform_coefficients`, respectively.
+Similarly you can do this for the radial polynomial coefficients and the NA transformed wavefront error expansion coefficients by importing the functions `radial_coefficients` and `transform_coefficients`, respectively.

src/Zernike.jl

@@ -12,7 +12,8 @@ export zernike, wavefront, transform, Z, W, P, WavefrontError,
        noll_to_j, fringe_to_j, standardize, standardize!,
        Observable, plotconfig, zplot
 
-# public metrics, coefficients, transform_coefficients, reconstruct, scale, J
+# public radial_coefficients, wavefront_coefficients, transform_coefficients,
+       # metrics, scale, J
 
 using GLMakie
 import .Makie: latexstring, LaTeXString
@@ -309,7 +310,8 @@ Z(j::Int) = Z(get_mn(j)...)
 const piston = Z(0, 0)
 
 # aliases for the API namespace
-const coefficients = Φ
-const transform_coefficients = S
+radial_coefficients(x...) = Φ(x...)[end]
+wavefront_coefficents(x...) = reconstruct(x...)[1]
+transform_coefficients(x...) = S(x...)[1]
 
 end

test/runtests.jl

@@ -45,7 +45,7 @@ function compare_coefficients(j_max)
         end
         i = j + 1
         zλ[i] = Z(m, n).R.λ
-        Φλ[i] = Zernike.coefficients(μ, n)[end]
+        Φλ[i] = Zernike.radial_coefficients(μ, n)[end]
     end
     m_max, n_max = last(mn)
     λ = Φ(m_max, n_max)