feat: validate parameter type and allow dependent initial values in param init

Author: AayushSabharwal

src/systems/nonlinear/initializesystem.jl

@@ -188,13 +188,16 @@ struct InitializationSystemMetadata
 end
 
 function is_parameter_solvable(p, pmap, defs, guesses)
+    p = unwrap(p)
+    is_variable_floatingpoint(p) || return false
     _val1 = pmap isa AbstractDict ? get(pmap, p, nothing) : nothing
     _val2 = get(defs, p, nothing)
     _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
+            (symbolic_type(_val1) != NotSymbolic() ||
+                _val1 === nothing && _val2 !== nothing)) && _val3 !== nothing
 end
 
 function SciMLBase.remake_initializeprob(sys::ODESystem, odefn, u0, t0, p)

src/utils.jl

@@ -885,3 +885,9 @@ end
 
 diff2term_with_unit(x, t) = _with_unit(diff2term, x, t)
 lower_varname_with_unit(var, iv, order) = _with_unit(lower_varname, var, iv, iv, order)
+
+function is_variable_floatingpoint(sym)
+    sym = unwrap(sym)
+    T = symtype(sym)
+    return T == Real || T <: AbstractFloat || T <: AbstractArray{Real} || T <: AbstractArray{<:AbstractFloat}
+end

test/initializationsystem.jl

@@ -637,21 +637,39 @@ sol = solve(oprob_2nd_order_2, Rosenbrock23()) # retcode: Success
     prob2.ps[p] = 0.0
     test_parameter(prob2, p, 2.0)
 
-    # Should not be solved for:
+    # Default overridden by ODEProblem, guess provided
+    @mtkbuild sys = ODESystem(
+        [D(x) ~ q * x, D(y) ~ y * p], t; defaults = [p => 2q], guesses = [p => 1.0])
+    _pmap = merge(pmap, Dict(p => q))
+    prob = ODEProblem(sys, u0map, (0.0, 1.0), _pmap)
+    test_parameter(prob, p, pmap[q])
+    test_initializesystem(sys, u0map, pmap, p, 0 ~ q - p)
 
-    # ODEProblem value with guess, no `missing`
+    # ODEProblem dependent value with guess, no `missing`
     @mtkbuild sys = ODESystem([D(x) ~ x * q, D(y) ~ y * p], t; guesses = [p => 0.0])
     _pmap = merge(pmap, Dict(p => 3q))
     prob = ODEProblem(sys, u0map, (0.0, 1.0), _pmap)
-    @test prob.ps[p] ≈ 3.0
-    @test prob.f.initializeprob === nothing
-    # Default overridden by ODEProblem, guess provided
+    test_parameter(prob, p, 3pmap[q])
+
+    # Should not be solved for:
+
+    # Override dependent default with direct value
     @mtkbuild sys = ODESystem(
         [D(x) ~ q * x, D(y) ~ y * p], t; defaults = [p => 2q], guesses = [p => 1.0])
+    _pmap = merge(pmap, Dict(p => 1.0))
     prob = ODEProblem(sys, u0map, (0.0, 1.0), _pmap)
-    @test prob.ps[p] ≈ 3.0
+    @test prob.ps[p] ≈ 1.0
     @test prob.f.initializeprob === nothing
 
+    # Non-floating point
+    @parameters r::Int s::Int
+    @mtkbuild sys = ODESystem(
+        [D(x) ~ s * x, D(y) ~ y * r], t; defaults = [s => 2r], guesses = [s => 1.0])
+    prob = ODEProblem(sys, u0map, (0.0, 1.0), [r => 1])
+    @test prob.ps[r] == 1
+    @test prob.ps[s] == 2
+    @test prob.f.initializeprob === nothing
+    
     @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))