Merge pull request #374 from SciML/multidim

multidimensional modelingtoolkitize support

Author: ChrisRackauckas

src/simplify.jl

@@ -36,6 +36,7 @@ SymbolicUtils.symtype(x::Expression) = Number
 # SymbolicUtils -> ModelingToolkit
 
 simplify(expr::Expression) = SymbolicUtils.simplify(expr) |> to_mtk
+simplify(x::Equation) = simplify(x.lhs) ~ simplify(x.rhs)
 simplify(expr) = expr |> to_mtk
 
 @deprecate simplify_constants(ex) simplify(ex)

src/systems/diffeqs/modelingtoolkitize.jl

@@ -7,9 +7,9 @@ function modelingtoolkitize(prob::DiffEqBase.ODEProblem)
     prob.f isa DiffEqBase.AbstractParameterizedFunction &&
                             return (prob.f.sys, prob.f.sys.states, prob.f.sys.ps)
     @parameters t
-    vars = [Variable(:x, i)(t) for i in eachindex(prob.u0)]
+    vars = reshape([Variable(:x, i)(t) for i in eachindex(prob.u0)],size(prob.u0))
     params = prob.p isa DiffEqBase.NullParameters ? [] :
-             [Variable(:α,i)() for i in eachindex(prob.p)]
+             reshape([Variable(:α,i)() for i in eachindex(prob.p)],size(prob.p))
     @derivatives D'~t
 
     rhs = [D(var) for var in vars]
@@ -22,7 +22,7 @@ function modelingtoolkitize(prob::DiffEqBase.ODEProblem)
     end
 
     eqs = vcat([rhs[i] ~ lhs[i] for i in eachindex(prob.u0)]...)
-    de = ODESystem(eqs,t,vars,params)
+    de = ODESystem(eqs,t,vec(vars),vec(params))
 
     de
 end