Merge pull request #147 from baggepinnen/errormsg

add better error message for invalid initial guess
baggepinnen · Nov 4, 2023 · 11e312a · 11e312a
2 parents 501e667 + 374bd9b
commit 11e312a
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diff --git a/docs/src/validation.md b/docs/src/validation.md
@@ -130,6 +130,9 @@ ControlSystemIdentification.aic
 - [`autocorplot`](@ref)
 - [`crosscorplot`](@ref)
 - [`modelfit`](@ref)
+- [`rms`](@ref)
+- [`mse`](@ref)
+- [`sse`](@ref)
 
 ## Video tutorials
 

diff --git a/ext/ControlSystemIdentificationLSOptExt.jl b/ext/ControlSystemIdentificationLSOptExt.jl
@@ -133,6 +133,15 @@ function _inner_pem(
     T = length(yvv)
     ny = size(R2, 1)
 
+    # Test the initial guess to give good error message
+    try
+        xp = discrete_dynamics(x0, uvv[1], p0, 0.0)
+        all(isfinite, xp) || throw(ArgumentError("Initial guess for x0 and p0 produced a non-finite state update ($xp). Improve the initial guess to avoid this error."))
+    catch e
+        @error "Aborting nonlinear PEM due to error in the dynamics update"
+        rethrow()
+    end
+
     res = optimize!(
         LeastSquaresProblem(;
             x = p_guess,

diff --git a/test/test_nonlinear_pem.jl b/test/test_nonlinear_pem.jl
@@ -1,7 +1,8 @@
 using ControlSystemIdentification, SeeToDee, LowLevelParticleFilters
 using LeastSquaresOptim
 using StaticArrays
-
+using LinearAlgebra
+using Test
 
 function quadtank(h, u, p, t)
     k1, k2, g = p[1], p[2], 9.81
@@ -60,6 +61,9 @@ isinteractive() && plot(d)
 x00 = 0.5*[2.5, 1.5, 3, 3]
 p0 = [1.4, 1.4, 5.1, 0.25]
 
+
+@test_throws "Initial" ControlSystemIdentification.nonlinear_pem(d, discrete_dynamics, measurement, p0, Inf*x00, R1, 100R2, nu)
+
 model = ControlSystemIdentification.nonlinear_pem(d, discrete_dynamics, measurement, p0, x00, R1, 100R2, nu)
 
 p_opt = model.p