add a parameter interface for PDE system and downstream test on NPDE

Author: ChrisRackauckas

.github/workflows/Downstream.yml

@@ -18,6 +18,7 @@ jobs:
         os: [ubuntu-latest]
         package:
           - {user: SciML, repo: Catalyst.jl, group: All}
+          - {user: SciML, repo: NeuralPDE.jl, group: NNPDE}
 
     steps:
       - uses: actions/checkout@v2

src/systems/pde/pdesystem.jl

@@ -4,9 +4,9 @@ struct PDESystem <: ModelingToolkit.AbstractSystem
   domain
   indvars
   depvars
-  
-  @add_kwonly function PDESystem(eqs, bcs, domain, indvars, depvars)
-      new(eqs, bcs, domain, indvars, depvars)
+  ps
+  @add_kwonly function PDESystem(eqs, bcs, domain, indvars, depvars, ps = SciMLBase.NullParameters())
+      new(eqs, bcs, domain, indvars, depvars, ps)
   end
 end
 
@@ -15,11 +15,11 @@ Base.getproperty(x::PDESystem, sym::Symbol) = getfield(x, sym)
 Base.summary(prob::PDESystem) = string(nameof(typeof(prob)))
 function Base.show(io::IO, sys::PDESystem)
   println(io,summary(sys))
-  println(io,"eqs: ", sys.eqs)
-  println(io,"bcs: ", sys.bcs)
-  println(io,"domain: ", sys.domain)
-  println(io,"depvars: ", sys.depvars)
-  println(io,"indvars: ", sys.indvars)
+  println(io,"Equations: ", sys.eqs)
+  println(io,"Boundary Conditions: ", sys.bcs)
+  println(io,"Domain: ", sys.domain)
+  println(io,"Dependent Variables: ", sys.depvars)
+  println(io,"Independent Variables: ", sys.indvars)
+  println(io,"Parameters: ", sys.ps)
   return nothing
 end
-