Merge pull request #333 from JuliaControl/debug_hold

debug: do not allow `h>1` in `OrthogonalCollocation`

Author: franckgaga

Project.toml

@@ -1,6 +1,6 @@
 name = "ModelPredictiveControl"
 uuid = "61f9bdb8-6ae4-484a-811f-bbf86720c31c"
-version = "2.1.0"
+version = "2.1.1"
 authors = ["Francis Gagnon"]
 
 [deps]

src/controller/transcription.jl

@@ -129,9 +129,9 @@ end
 Construct an orthogonal collocation on finite elements [`TranscriptionMethod`](@ref).
 
 Also known as pseudo-spectral method. It supports continuous-time [`NonLinModel`](@ref)s
-only. The `h` argument is the hold order for ``\mathbf{u}``, and the `no` argument, the
-number of collocation points ``n_o``. The decision variable is similar to [`MultipleShooting`](@ref),
-but it also includes the collocation points:
+only. The `h` argument is the hold order for ``\mathbf{u}`` (`0` or `1`), and the `no`
+argument, the number of collocation points ``n_o``. The decision variable is similar to
+[`MultipleShooting`](@ref), but it also includes the collocation points:
 ```math
 \mathbf{Z} = \begin{bmatrix} \mathbf{ΔU} \\ \mathbf{X̂_0} \\ \mathbf{K} \end{bmatrix}
 ```
@@ -186,6 +186,9 @@ struct OrthogonalCollocation <: CollocationMethod
     function OrthogonalCollocation(
         h::Int=0, no::Int=3; f_threads=false, h_threads=false, roots=:gaussradau
     )
+        if !(h == 0 || h == 1)
+            throw(ArgumentError("h argument must be 0 or 1 for OrthogonalCollocation."))
+        end
         if roots==:gaussradau            
             x, _ = FastGaussQuadrature.gaussradau(no, COLLOCATION_NODE_TYPE)
             # we reverse the nodes to include the τ=1.0 node:

test/3_test_predictive_control.jl

@@ -877,10 +877,11 @@ end
     @test isa(nmpc15.optim, JuMP.GenericModel{Float64}) # Ipopt does not support Float32
 
     @test_throws ArgumentError NonLinMPC(nonlinmodel)
-    @test_throws ArgumentError NonLinMPC(nonlinmodel, Hp=2, transcription=TrapezoidalCollocation())
-    @test_throws ArgumentError NonLinMPC(nonlinmodel, Hp=2, transcription=TrapezoidalCollocation(2))
     @test_throws ArgumentError NonLinMPC(nonlinmodel, Hp=2, Wy=[1 0;0 1])
+    @test_throws ArgumentError NonLinMPC(nonlinmodel, Hp=2, transcription=TrapezoidalCollocation())
+    @test_throws ArgumentError TrapezoidalCollocation(2)
     @test_throws ArgumentError OrthogonalCollocation(roots=:gausslobatto)
+    @test_throws ArgumentError OrthogonalCollocation(2)
 end
 
 @testitem "NonLinMPC moves and getinfo (LinModel)" setup=[SetupMPCtests] begin