new convergence tests

to be build up in a later pr

Author: yash-rs

test/convergencetests.jl

@@ -0,0 +1,38 @@
+using NonlinearSolve
+using StaticArrays
+using BenchmarkTools
+using Test
+
+using SciMLNLSolve
+
+###-----Trust Region tests-----###
+
+# some simple functions #
+function f_oop(u, p)
+    u .* u .- p
+end
+
+function f_iip(du, u, p)
+    du .= u .* u .- p
+end
+
+function f_scalar(u, p)
+    u * u - p
+end
+
+u0 = [1.0, 1.0]
+csu0 = 1.0
+p = [2.0, 2.0]
+radius_update_scheme = RadiusUpdateSchemes.Simple
+tol = 1e-9
+
+function convergence_test_oop(f, u0, p, radius_update_scheme)
+    prob = NonlinearProblem{false}(f, oftype(p, u0), p)
+    cache = init(prob, TrustRegion(radius_update_scheme=radius_update_scheme), abstol = 1e-9)
+    sol = solve!(cache)
+    return cache.internalnorm(cache.u_prev - cache.u), cache.iter, sol.retcode
+end
+
+residual, iterations, return_code = convergence_test_oop(f_oop, u0, p, radius_update_scheme)
+@test return_code === ReturnCode.Success
+@test residual ≈ tol