fix #991, support symbolic parameters at problem level

Author: pepijndevos

src/systems/diffeqs/abstractodesystem.jl

@@ -398,15 +398,15 @@ function process_DEProblem(constructor, sys::AbstractODESystem,u0map,parammap;
     defs = defaults(sys)
     iv = independent_variable(sys)
 
-    u0 = varmap_to_vars(u0map,dvs; defaults=defs)
+    u0 = varmap_to_vars(u0map,dvs; defaults=merge(defs, Dict(parammap)))
     if implicit_dae && du0map !== nothing
         ddvs = map(Differential(iv), dvs)
         du0 = varmap_to_vars(du0map, ddvs; defaults=defaults, toterm=identity)
     else
         du0 = nothing
         ddvs = nothing
     end
-    p = varmap_to_vars(parammap,ps; defaults=defs)
+    p = varmap_to_vars(parammap,ps; defaults=merge(defs, Dict(u0map)))
 
     check_eqs_u0(eqs, dvs, u0)
 

test/symbolic_parameters.jl

@@ -45,3 +45,24 @@ prob = NonlinearProblem(top, [states(ns, u)=>1.0, a=>1.0], Pair[])
 prob = NonlinearProblem(top, [states(ns, u)=>1.0, a=>1.0])
 @test prob.u0 == [1.0, 0.5, 1.1, 0.9]
 @show sol = solve(prob,NewtonRaphson())
+
+# test initial conditions and parameters at the problem level
+pars = @parameters(begin
+                   x0
+                   t
+                   end)
+vars = @variables(begin
+                  x(t)
+                  end)
+der = Differential(t)
+eqs = [der(x) ~ x]
+sys = ODESystem(eqs, t, vars, [x0])
+pars = [
+  x0 => 10.0,
+]
+initialValues = [
+  x => x0
+]
+tspan = (0.0, 1.0)
+problem = ODEProblem(sys, initialValues, tspan, pars)
+@test problem.u0 isa Vector{Float64}