Remove process_trajectory_symmetrize from public docs

For experts, a keyword argument with the same name still exists, but now accepts a function rather than symbol.

docs/src/versions.md

@@ -10,11 +10,12 @@
   experimental function [`modify_exchange_with_truncated_dipole_dipole!`](@ref)
   will accept a real-space cutoff.
 * Intensities calculated with [`dynamical_correlations`](@ref) now avoid
-  "smearing artifacts" at gapless modes. See [PR
-  246](https://github.com/SunnySuite/Sunny.jl/pull/246) for details.
-* In dipole mode, fix bugs to support the case that spin-``S`` varies between
-  sites. In SU(``N``) mode, however, there is still no support for varying
-  the Hilbert space dimension ``N`` between sites.
+  "smearing artifacts" at low-energy (long-timescale) modes. See [PR
+  246](https://github.com/SunnySuite/Sunny.jl/pull/246) for details. This
+  eliminates the need for `process_trajectory=:symmetrize`.
+* In dipole mode, having spin-``S`` vary between sites was previously broken,
+  and is now fixed. In SU(``N``) mode, however, there is still no support for
+  varying the Hilbert space dimension ``N`` between sites.
 * Long-range dipole-dipole was previously broken for systems with multiple
   cells, but is now fixed.
 * General biquadratic interactions (beyond scalar) in dipole mode are fixed in

docs/src/writevtk.md

@@ -44,7 +44,7 @@ end
 
 ωmax=10.
 
-dsf = dynamical_correlations(sys; dt, nω=48, ωmax, process_trajectory=:symmetrize)
+dsf = dynamical_correlations(sys; dt, nω=48, ωmax)
 
 nsamples = 10
 for _ in 1:nsamples

examples/03_LLD_CoRh2O4.jl

@@ -132,7 +132,7 @@ heatmap(q1s, q2s, iq;
 dt = 2*langevin.dt
 ωmax = 6.0  # Maximum energy to resolve (meV)
 nω = 50     # Number of energies to resolve
-sc = dynamical_correlations(sys; dt, nω, ωmax, process_trajectory=:symmetrize)
+sc = dynamical_correlations(sys; dt, nω, ωmax)
 
 # Use Langevin dynamics to sample spin configurations from thermal equilibrium.
 # For each sample, use [`add_sample!`](@ref) to run a classical spin dynamics

src/SampledCorrelations/CorrelationSampling.jl

@@ -60,17 +60,6 @@ function new_sample!(sc::SampledCorrelations, sys::System)
     return nothing
 end
 
-# At the sacrifice of code modularity, this processing step could be effected
-# more efficiently by simply taking the real part of the trajectory after the
-# Fourier transform
-function symmetrize!(sc::SampledCorrelations)
-    (; samplebuf) = sc
-    nsteps = size(samplebuf, 6)
-    mid = floor(Int, nsteps/2)
-    for t in 1:mid, idx in CartesianIndices(size(samplebuf)[1:5])
-        samplebuf[idx, t] = samplebuf[idx, nsteps-t+1] = 0.5*(samplebuf[idx, t] + samplebuf[idx, nsteps-t+1])
-    end
-end
 
 function subtract_mean!(sc::SampledCorrelations)
     (; samplebuf) = sc

src/SampledCorrelations/SampledCorrelations.jl

@@ -88,7 +88,7 @@ end
 
 """
     dynamical_correlations(sys::System; dt, nω, ωmax, 
-        process_trajectory=:none, observables=nothing, correlations=nothing) 
+                           observables=nothing, correlations=nothing) 
 
 Creates an empty `SampledCorrelations` object for calculating and storing
 dynamical structure factor intensities ``𝒮(𝐪,ω)``. Call [`add_sample!`](@ref)
@@ -125,12 +125,16 @@ Additional keyword options are the following:
 """
 function dynamical_correlations(sys::System{N}; dt=nothing, Δt=nothing, nω, ωmax,
                                 apply_g=true, observables=nothing, correlations=nothing,
-                                calculate_errors=false, process_trajectory=:none) where N
+                                calculate_errors=false, process_trajectory=no_processing) where N
     if !isnothing(Δt)
         @warn "`Δt` argument is deprecated! Use `dt` instead."
         dt = @something dt Δt
     end
     isnothing(dt) && error("`dt` parameter required")
+    if process_trajectory == :symmetrize
+        @warn "`process_trajectory=:symmetrize` is deprecated and will be ignored"
+        process_trajectory = no_processing
+    end
 
     observables = parse_observables(N; observables, correlations, g = apply_g ? sys.gs : nothing)
 
@@ -152,17 +156,6 @@ function dynamical_correlations(sys::System{N}; dt=nothing, Δt=nothing, nω, ω
         Δω = 2π / (dt*measperiod*n_all_ω)
     end
 
-    # Set up trajectory processing function (e.g., symmetrize)
-    processtraj! = if process_trajectory == :none 
-        no_processing
-    elseif process_trajectory == :symmetrize
-        symmetrize!
-    elseif process_trajectory == :subtract_mean
-        subtract_mean!
-    else
-        error("Unknown argument for `process_trajectory`")
-    end
-
     # Preallocation
     na = natoms(sys.crystal)
 
@@ -186,7 +179,7 @@ function dynamical_correlations(sys::System{N}; dt=nothing, Δt=nothing, nω, ω
     # Make Structure factor and add an initial sample
     origin_crystal = isnothing(sys.origin) ? nothing : sys.origin.crystal
     sc = SampledCorrelations{N}(data, M, sys.crystal, origin_crystal, Δω, observables,
-                                samplebuf, fft!, measperiod, apply_g, dt, nsamples, processtraj!)
+                                samplebuf, fft!, measperiod, apply_g, dt, nsamples, process_trajectory)
 
     return sc
 end