fix: require guesses for parameters

Author: AayushSabharwal

src/systems/nonlinear/initializesystem.jl

@@ -119,7 +119,7 @@ function generate_initializesystem(sys::ODESystem;
                     push!(u0, varp => _val1)
                 elseif _val3 !== nothing
                     # assuming an equation exists (either via algebraic equations or initialization_eqs)
-                    push!(u0, varp => _val1)
+                    push!(u0, varp => _val3)
                 elseif check_defguess
                     error("Invalid setup: parameter $(p) has no default value, initial value, or guess")
                 end
@@ -129,7 +129,7 @@ function generate_initializesystem(sys::ODESystem;
                     push!(eqs_ics, varp ~ _val2)
                     push!(u0, varp => _val2)
                 elseif _val3 !== nothing
-                    push!(u0, varp => _val1)
+                    push!(u0, varp => _val3)
                 elseif check_defguess
                     error("Invalid setup: parameter $(p) has no default value, initial value, or guess")
                 end
@@ -186,8 +186,8 @@ function is_parameter_solvable(p, pmap, defs, guesses)
     _val3 = get(guesses, p, nothing)
     # either (missing is a default or was passed to the ODEProblem) or (nothing was passed to
     # the ODEProblem and it has a default and a guess)
-    return (_val1 === missing || _val2 === missing) ||
-           (_val1 === nothing && _val2 !== nothing && _val3 !== nothing)
+    return ((_val1 === missing || _val2 === missing) ||
+           (_val1 === nothing && _val2 !== nothing)) && _val3 !== nothing
 end
 
 function SciMLBase.remake_initializeprob(sys::ODESystem, odefn, u0, t0, p)

test/initializationsystem.jl

@@ -587,7 +587,7 @@ sol = solve(oprob_2nd_order_2, Rosenbrock23()) # retcode: Success
     pmap = Dict()
     pmap[q] = 1.0
     # `missing` default, equation from ODEProblem
-    @mtkbuild sys = ODESystem([D(x) ~ x * q, D(y) ~ y * p], t; defaults = [p => missing])
+    @mtkbuild sys = ODESystem([D(x) ~ x * q, D(y) ~ y * p], t; defaults = [p => missing], guesses = [p => 1.0])
     pmap[p] = 2q
     prob = ODEProblem(sys, u0map, (0.0, 1.0), pmap)
     test_parameter(prob, p, 2.0)
@@ -605,7 +605,7 @@ sol = solve(oprob_2nd_order_2, Rosenbrock23()) # retcode: Success
     test_parameter(prob2, p, 2.0)
 
     # `missing` to ODEProblem, equation from default
-    @mtkbuild sys = ODESystem([D(x) ~ x * q, D(y) ~ y * p], t; defaults = [p => 2q])
+    @mtkbuild sys = ODESystem([D(x) ~ x * q, D(y) ~ y * p], t; defaults = [p => 2q], guesses = [p => 1.0])
     pmap[p] = missing
     prob = ODEProblem(sys, u0map, (0.0, 1.0), pmap)
     test_parameter(prob, p, 2.0)
@@ -652,9 +652,6 @@ sol = solve(oprob_2nd_order_2, Rosenbrock23()) # retcode: Success
     @mtkbuild sys = ODESystem([D(x) ~ x, p ~ x + y], t; guesses = [p => 0.0])
     @test_throws ModelingToolkit.MissingParametersError ODEProblem(
         sys, [x => 1.0, y => 1.0], (0.0, 1.0))
-    @mtkbuild sys = ODESystem([D(x) ~ x, p ~ x + y], t)
-    @test_throws ["Invalid setup", "parameter p", "guess"] ModelingToolkit.generate_initializesystem(
-        sys; u0map = Dict(x => 1.0, y => 1.0), pmap = Dict(p => missing), check_defguess = true)
 
     @testset "Null system" begin
         @variables x(t) y(t) s(t)
@@ -726,3 +723,13 @@ end
     @test init(prob2, Tsit5())[x] ≈ 0.5
     @test_nowarn solve(prob2, Tsit5())
 end
+
+@testset "Equations for dependent parameters" begin
+    @variables x(t)
+    @parameters p q = 5 r
+    @mtkbuild sys = ODESystem(D(x) ~ 2x + r, t; parameter_dependencies = [r ~ p + 2q, q ~ p + 3], guesses = [p => 1.0])
+    prob = ODEProblem(sys, [x => 1.0], (0.0, 1.0), [p => missing])
+    @test length(equations(ModelingToolkit.get_parent(prob.f.initializeprob.f.sys))) == 4
+    integ = init(prob, Tsit5())
+    @test integ.ps[p] ≈ 2
+end