update

Author: TorkelE

src/reaction_network.jl

@@ -410,14 +410,14 @@ function make_reaction_system(ex::Expr; name = :(gensym(:ReactionSystem)))
     pexprs = get_pexpr(parameters_extracted, options)
     ns_ps, ns_pssym = scalarize_macro(haskey(options, :noise_scaling_parameters), noise_scaling_pexpr, "ns_ps")
     ps, pssym = scalarize_macro(!isempty(parameters), pexprs, "ps")
+    rs_p_syms = haskey(options, :noise_scaling_parameters) ? :(union($pssym, $ns_pssym)) : pssym
     vars, varssym = scalarize_macro(!isempty(variables), vexprs, "vars")
     sps, spssym = scalarize_macro(!isempty(species), sexprs, "specs")
     comps, compssym = scalarize_macro(!isempty(compound_species), compound_expr, "comps")
     rxexprs = :(Catalyst.CatalystEqType[])
     for reaction in reactions
         push!(rxexprs.args, get_rxexprs(reaction))
     end
-
     # Returns the rephrased expression.
     quote
         $ps

src/reactionsystem.jl

@@ -1500,7 +1500,7 @@ Notes:
   differential equations.
 """
 function Base.convert(::Type{<:SDESystem}, rs::ReactionSystem;
-                      noise_scaling = get_noise_scaling(rs), name = nameof(rs),
+                      noise_scaling = nothing, name = nameof(rs),
                       combinatoric_ratelaws = get_combinatoric_ratelaws(rs),
                       include_zero_odes = true, checks = false, remove_conserved = false,
                       default_u0 = Dict(), default_p = Dict(), defaults = _merge(Dict(default_u0), Dict(default_p)),
@@ -1510,7 +1510,13 @@ function Base.convert(::Type{<:SDESystem}, rs::ReactionSystem;
     flatrs = Catalyst.flatten(rs)
     error_if_constraints(SDESystem, flatrs)
 
-    isnothing(noise_scaling) && (noise_scaling = get_noise_scaling(rs)) # Required until passing nosie into SDEProblem can be depricated.
+    # Required until passing nosie into SDEProblem can be depricated. When properly deprecated, change the kwarg to noise_scaling = get_noise_scaling(rs).
+    if !isnothing(noise_scaling)
+        !isnothing(get_noise_scaling(rs)) && error("You have declared some parameters as noise scaling parameters, and also given a \"noise_scaling\" argument to SDEProblem. Please remove the \"noise_scaling\", as this way of scaling CLE noise is being depricated.")
+        @warn "Passing noise scaling input into SDEProblem will be deprecated. New standard is to declare one (or several) paraemter as noise scaling parameters when the ReactionSystem is created. Please read https://docs.sciml.ai/Catalyst/stable/catalyst_applications/advanced_simulations/#Scaling-the-noise-magnitude-in-the-chemical-Langevin-equations." 
+    end
+    isnothing(noise_scaling) && (noise_scaling = get_noise_scaling(flatrs)) 
+    
     if noise_scaling isa AbstractArray
         (length(noise_scaling) != numreactions(flatrs)) &&
             error("The number of elements in 'noise_scaling' must be equal " *
@@ -1551,7 +1557,7 @@ function get_noise_scaling(rs::ReactionSystem)
     if isempty(ns_params)
         return nothing
     elseif length(ns_params) == 1
-        return Num(ns_params[1])
+        return ns_params[1]
     elseif length(ns_params) == length(reactions(rs)) 
         return ns_params
     else
@@ -1648,11 +1654,6 @@ function DiffEqBase.SDEProblem(rs::ReactionSystem, u0, tspan,
                                check_length = false,
                                remove_conserved = false, kwargs...)
 
-    if !isnothing(noise_scaling)
-        !isnothing(get_noise_scaling(rs)) && error("You have declared some parameters as noise scaling parameters, and also given a \"noise_scaling\" argument to SDEProblem. Please remove the \"noise_scaling\", as this way of scaling CLE noise is being depricated.")
-        @warn "Passing noise scaling input into SDEProblem will be deprecated. New standard is to declare one (or several) paraemter as noise scaling parameters when the ReactionSystem is created. Please read https://docs.sciml.ai/Catalyst/stable/catalyst_applications/advanced_simulations/#Scaling-the-noise-magnitude-in-the-chemical-Langevin-equations." 
-    end
-
     u0map = symmap_to_varmap(rs, u0)
     pmap = symmap_to_varmap(rs, p)
     sde_sys = convert(SDESystem, rs; noise_scaling, name, combinatoric_ratelaws,