Merge pull request #1645 from jedforrest/fix-SDE-rename

removed SDESystem rename function

Author: YingboMa

src/systems/diffeqs/sdesystem.jl

@@ -368,11 +368,6 @@ function SDEFunctionExpr(sys::SDESystem, args...; kwargs...)
     SDEFunctionExpr{true}(sys, args...; kwargs...)
 end
 
-function rename(sys::SDESystem, name)
-    SDESystem(sys.eqs, sys.noiseeqs, sys.iv, sys.states, sys.ps, sys.tgrad, sys.jac,
-              sys.Wfact, sys.Wfact_t, name, sys.systems, checks = false)
-end
-
 """
 ```julia
 function DiffEqBase.SDEProblem{iip}(sys::SDESystem,u0map,tspan,p=parammap;

test/sdesystem.jl

@@ -471,3 +471,11 @@ D = Differential(t)
 RHS2 = RHS
 @unpack RHS = fol
 @test isequal(RHS, RHS2)
+
+# issue #1644
+using ModelingToolkit: rename
+@variables t
+eqs = [D(x) ~ x]
+noiseeqs = [0.1 * x]
+@named de = SDESystem(eqs, noiseeqs, t, [x], [])
+@test nameof(rename(de, :newname)) == :newname