Bifurcation kit extension

Project.toml

@@ -51,9 +51,11 @@ UnPack = "3a884ed6-31ef-47d7-9d2a-63182c4928ed"
 Unitful = "1986cc42-f94f-5a68-af5c-568840ba703d"
 
 [weakdeps]
+BifurcationKit = "0f109fa4-8a5d-4b75-95aa-f515264e7665"
 DeepDiffs = "ab62b9b5-e342-54a8-a765-a90f495de1a6"
 
 [extensions]
+MTKBifurcationKitExt = "BifurcationKit"
 MTKDeepDiffsExt = "DeepDiffs"
 
 [compat]

ext/MTKBifurcationKitExt.jl

@@ -0,0 +1,40 @@
+module MTKBifurcationKitExt
+
+println("BifurcationKit extension loaded")
+
+### Preparations ###
+
+# Imports
+using ModelingToolkit, Setfield
+import BifurcationKit
+
+### Creates BifurcationProblem Overloads ###
+
+# When input is a NonlinearSystem.
+function BifurcationKit.BifurcationProblem(nsys::NonlinearSystem, u0_guess, p_start, bif_par, args...; plot_var=nothing, record_from_solution=BifurcationKit.record_sol_default, kwargs...)
+    # Creates F and J functions.
+    ofun = NonlinearFunction(nsys; jac=true)
+    F = ofun.f
+    J = ofun.jac
+
+    # Computes bifurcation parameter and plot var indexes.
+    bif_idx = findfirst(isequal(bif_par), parameters(nsys))
+    if !isnothing(plot_var) 
+        plot_idx = findfirst(isequal(plot_var), states(nsys))
+        record_from_solution = (x, p) -> x[plot_idx]
+    end
+
+    # Converts the input state guess.
+    u0_guess = ModelingToolkit.varmap_to_vars(u0_guess, states(nsys))
+
+    return BifurcationKit.BifurcationProblem(F, u0_guess, [p_start], (@lens _[1]), args...; record_from_solution = record_from_solution, J = J, kwargs...)
+end
+
+# When input is a ODESystem.
+function BifurcationKit.BifurcationProblem(osys::ODESystem, u0, p, args...; kwargs...)
+    return BifurcationProblem(convert(NonlinearProblem, osys), args...; kwargs...)
+end
+
+
+
+end # module